UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM N-CSR

              CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT
                              INVESTMENT COMPANIES

Investment Company Act file number   811-5531
                                   ---------------------------------------------



                       MassMutual Participation Investors
--------------------------------------------------------------------------------
               (Exact name of registrant as specified in charter)


          1500 Main Street, P.O. Box 15189, Springfield, MA 01115-5189
--------------------------------------------------------------------------------
              (Address of principal executive offices) (Zip code)


      Patricia J. Walsh, Vice President, Secretary and Chief Legal Officer
    1500 Main Street, Suite 2800, P.O. Box 15189, Springfield, MA 01115-5189
--------------------------------------------------------------------------------
                    (Name and address of agent for service)


Registrant's telephone number, including area code:  413-226-1000
                                                    ----------------------------

Date of fiscal year end:  12/31
                          ------------------

Date of reporting period: 06/30/10
                          ------------------

Form N-CSR is to be used by management investment companies to file reports with
the Commission not later than 10 days after the transmission to stockholders of
any report that is required to be transmitted to stockholders under Rule 30e-1
under the Investment Company Act of 1940 (17 CFR 270.30e-1). The Commission may
use the information provided on Form N-CSR in its regulatory, disclosure review,
inspection and policymaking roles.

A registrant is required to disclose the information specified by Form N-CSR,
and the Commission will make this information public. A registrant is not
required to respond to the collection of information contained in Form N-CSR
unless the Form displays a currently valid Office of Management and Budget
("OMB") control number. Please direct comments concerning the accuracy of the
information collection burden estimate and any suggestions for reducing the
burden to Secretary, Securities and Exchange Commission, 110 F Street NE,
Washington, DC 20549. The OMB has reviewed this collection of information under
the clearance requirements of 44 U.S.C. ss. 3507.


ITEM 1.  REPORT TO STOCKHOLDERS.

         Attached hereto is the semi-annual shareholder report transmitted to
         shareholders pursuant to Rule 30e-1 of the Investment Company Act of
         1940, as amended.







                                                                      MASSMUTUAL
                                                         PARTICIPATION INVESTORS

                                                                  REPORT FOR THE
                                                  SIX MONTHS ENDED JUNE 30, 2010



                                                                          [LOGO]












ADVISER
Babson Capital Management LLC *
1500 Main Street, P.O. Box 15189
Springfield, Massachusetts 01115-5189

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
KPMG LLP
Boston, Massachusetts 02110

COUNSEL TO THE TRUST
Ropes & Gray LLP
Boston, Massachusetts 02110

CUSTODIAN
Citibank, N.A.
New York, New York 10043

TRANSFER AGENT & REGISTRAR
Shareholder Financial Services, Inc. *
P.O. Box 173673
Denver, Colorado 80217-3673
1-800-647-7374

INTERNET WEBSITE
www.babsoncapital.com/mpv
            MassMutual Participation Investors
            c/o Babson Capital Management LLC
[LOGO]      1500 Main Street, Suite 2200
            Springfield, Massachusetts 01115
            (413) 226-1516

* Member of the MassMutual Financial Group
---------------------------------------------------------------------------

INVESTMENT OBJECTIVE AND POLICY

MassMutual  Participation  Investors  (the  "Trust")  is a closed-end management
investment company, first offered to the public in 1988, whose shares are traded
on the New York Stock Exchange under the trading symbol "MPV". The Trust's share
price  can  be found in the financial section of most newspapers as "MassPrt" or
"MassMuPrt" under either the New York Stock Exchange listings or Closed-End Fund
Listings.

The Trust's investment objective is to maximize total return by providing a high
level  of  current  income,  the  potential  for  growth  of income, and capital
appreciation.   The   Trust's   principal   investments  are  privately  placed,
below-investment grade, long-term debt obligations purchased directly from their
issuers,  which tend to be smaller companies. At least half of these investments
normally  include  equity  features  such  as common stock, warrants, conversion
rights,  or other equity features that provide the Trust with the opportunity to
realize  capital  gains.  The  Trust  will  also  invest in publicly traded debt
securities  (including  high  yield securities), again with an emphasis on those
with  equity  features,  and  in  convertible  preferred  stocks and, subject to
certain  limitations,  readily  marketable  equity  securities. Below-investment
grade  or  high  yield securities have predominantly speculative characteristics
with  respect to the capacity of the issuer to pay interest and repay principal.
In  addition,  the  Trust  may  temporarily  invest  in  high  quality,  readily
marketable securities.

Babson  Capital  Management  LLC ("Babson Capital") manages the Trust on a total
return  basis.  The  Trust  distributes  substantially  all of its net income to
shareholders each year. Accordingly, the Trust pays dividends to shareholders in
January,   May,   August,   and   November.   All  registered  shareholders  are
automatically  enrolled  in  the  Dividend  Reinvestment  and Cash Purchase Plan
unless cash distributions are requested.

FORM N-Q
The  Trust  files  its  complete  schedule  of  portfolio holdings with the U.S.
Securities  and  Exchange Commission ("SEC") for the first and third quarters of
each  fiscal  year  on  Form N-Q. This information is available (i) on the SEC's
website  at  http://www.sec.gov;  and (ii) at the SEC's Public Reference Room in
Washington,  DC (which information on their operation may be obtained by calling
1-800-SEC-0330).   A   complete  schedule  of  portfolio  holdings  as  of  each
quarter-end is available upon request by calling, toll-free, 866-399-1516.

PROXY VOTING POLICIES & PROCEDURES; PROXY VOTING RECORD
The  Trustees of the Trust have delegated proxy voting responsibilities relating
to  the  voting of securities held by the Trust to Babson Capital. A description
of  Babson  Capital's  proxy  voting  policies  and  procedures is available (1)
without  charge,  upon  request,  by calling, toll-free 866-399-1516; (2) on the
Trust's  website: http://www.babsoncapital.com/mpv; and (3) on the SEC's website
at  http://www.sec.gov.  Information  regarding  how  the  Trust  voted  proxies
relating  to  portfolio  securities during the most recent 12-month period ended
June     30     is     available     (1)     on     the     Trust's     website:
http://www.babsoncapital.com/mpv;    and   (2)   on   the   SEC's   website   at
http://www.sec.gov.


MPV
LISTED
NYSE

                                              MassMutual Participation Investors

TO OUR SHAREHOLDERS

July 31, 2010
We  are  pleased  to  present  the  June 30, 2010 Quarterly Report of MassMutual
Participation Investors (the "Trust").

The  Board  of  Trustees  declared  a  quarterly dividend of 25 cents per share,
payable  on  August  13,  2010  to shareholders of record on August 2, 2010. The
Trust  paid  a  25  cent per share dividend for the preceding quarter. The Trust
earned  24  cents  per  share of net investment income for the second quarter of
2010, compared to 24 cents per share in the previous quarter.

During the second quarter, the net assets of the Trust increased to $114,929,455
or  $11.47  per  share compared to $111,638,992 or $11.16 per share on March 31,
2010.  This  translates  into  a 5.1% total return for the quarter, based on the
change  in  the  Trust's  net assets assuming the reinvestment of all dividends.
Longer term, the Trust returned 13.5%, 4.6%, 9.7%, and 10.7% for the 1-, 3-, 5-,
and  10-year  time periods, respectively, based on the change in the Trust's net
assets assuming the reinvestment of all dividends.

The  Trust's  market  price  increased  3.3% during the quarter, from $12.50 per
share  as of March 31, 2010 to $12.91 per share as of June 30, 2010. The Trust's
market  price  of  $12.91 per share equates to a 12.6% premium over the June 30,
2010  net  asset  value  per  share  of  $11.47. The Trust's average quarter-end
premium  for  the  3-,  5-,  and  10-year  periods  was  1.2%,  6.6%  and  6.7%,
respectively.  U.S.  equity  markets, as approximated by the Russell 2000 Index,
decreased  9.9%  for  the quarter. U.S. fixed income markets, as approximated by
the  Barclays  Capital  U.S.  Corporate High Yield Index, decreased 0.1% for the
quarter.

The  Trust  closed  two  new  private  placement  investments  during the second
quarter.  The two new investments were in O E C Holdings Corporation and Wheaton
Holding  Corporation.  A  brief description of these investments can be found in
the Consolidated Schedule of Investments. The total amount invested by the Trust
in these two transactions was $1,500,000.

The  amount of debt and equity capital available to finance middle market buyout
transactions  continued  to  increase during the second quarter. As a result, we
saw  an  improving level of deal flow as the quarter progressed. Our contacts in
the  private equity and investment banking community indicate they currently are
very busy processing a large number of potential transactions, so we expect deal
flow  during  the  remainder  of  2010 to be very robust. Hopefully, this higher
level  of deal flow translates into a number of new investments for the Trust in
the  second  half of the year. Leverage multiples continued to expand during the
quarter  as capital providers aggressively pursued deal opportunities. We expect
leverage  multiples  to  continue  to  increase during the rest of the year. The
downward  pressure  on  pricing  and  return  expectations  moderated during the
quarter  and  we  expect a relatively stable pricing environment for the rest of
the year. As I have stated in prior quarters, despite constantly changing market
conditions,  our  approach  to  investing  will  not change. We will continue to
maintain  the  same  discipline  and  investment  philosophy that has served our
shareholders well for so many years.

As  the  economy  continued  to  rebound  during the second quarter, the overall
condition  of  our  portfolio  continued to improve as well. It was particularly
refreshing  to  see  many  of  our  underperforming  companies  start  to report
increased  sales and earnings. In several situations where we had been deferring
interest  on our subordinated notes, performance improved to the point where the
portfolio  company  was  able  to  resume  paying  cash  interest  on our notes.
Realization   activity,   which   generally   correlates  highly  with  improved
performance,  also  increased  as  the quarter progressed. We had two companies,
Diversco,  Inc.  and K-Tek Holding Corporation, successfully sold in early July.
There  continues  to  be a significant number of portfolio companies that are in
various stages of a sale process and we are hopeful that many of these will turn
into successful realizations in the upcoming quarters.

Thank you for your continued interest in and support of MassMutual Participation
Investors.

Sincerely,

/s/ Michael L. Klofas
Michael L. Klofas
President


                            [PIE CHART APPEARS HERE]
                       Portfolio Composition as of 6/30/10 *

Private / 144A High                     Public High Yield
Yield Debt                              Debt
70.7%                                   14.0%

Private / Restricted                    Public Equity
Equity                                  0.4%
12.8%

Cash & Short Term
Investments
2.1%

* Based on market value of total investments (including cash)
Cautionary  Notice:  Certain statements contained in this report may be "forward
looking"  statements.  Investors  are  cautioned  not to place undue reliance on
forward-looking  statements,  which  speak only as of the date on which they are
made and which reflect management's current estimates, projections, expectations
or  beliefs,  and  which  are  subject to risks and uncertainties that may cause
actual  results  to differ materially. These statements are subject to change at
any  time  based upon economic, market or other conditions and may not be relied
upon  as  investment  advice  or  an  indication  of the Trust's trading intent.
References  to  specific  securities are not recommendations of such securities,
and  may  not be representative of the Trust's current or future investments. We
undertake  no  obligation to publicly update forward looking statements, whether
as a result of new information, future events, or otherwise.


CONSOLIDATED STATEMENT OF ASSETS AND LIABILITIES
JUNE 30, 2010
(UNAUDITED)


                                                                             
ASSETS:
Investments
        (See Consolidated Schedule of Investments)
  Corporate restricted securities at fair value
        (Cost - $115,142,081)                                                   $ 99,640,015
  Corporate restricted securities at market value
        (Cost - $  4,127,163)                                                      4,150,991
  Corporate public securities at market value
        (Cost - $ 18,680,087)                                                     17,951,075
  Short-term securities at amortized cost                                          1,249,894
                                                                                ------------
                                                                                 122,991,975

Cash                                                                               1,419,608
Interest receivable                                                                2,942,182
Receivable for investments sold                                                      142,982
Other assets                                                                          12,569
                                                                                ------------
        TOTAL ASSETS                                                             127,509,316
                                                                                ------------

LIABILITIES:
Investment advisory fee payable                                                      258,591
Note payable                                                                      12,000,000
Interest payable                                                                      88,933
Accrued expenses                                                                     130,196
Accrued taxes payable                                                                 76,208
Other payables                                                                        25,933
                                                                                ------------
TOTAL LIABILITIES                                                                 12,579,861
                                                                                ------------
TOTAL NET ASSETS                                                                $114,929,455
                                                                                ============

NET ASSETS:
Common shares, par value $.01 per share; an unlimited number authorized         $    100,186
Additional paid-in capital                                                        93,521,296
Retained net realized gain on investments, prior years                            32,871,737
Undistributed net investment income                                                3,577,580
Accumulated net realized gain on investments                                       1,142,114
Net unrealized depreciation of investments                                       (16,283,458)
                                                                                ------------
TOTAL NET ASSETS                                                                $114,929,455
                                                                                ============
COMMON SHARES ISSUED AND OUTSTANDING                                              10,018,644
                                                                                ============
NET ASSET VALUE PER SHARE                                                       $      11.47
                                                                                ============


See Notes to Consolidated Financial Statements
--------------------------------------------------------------------------------
2

                                              MassMutual Participation Investors

CONSOLIDATED STATEMENT OF OPERATIONS
FOR THE SIX MONTHS ENDED JUNE 30, 2010
(UNAUDITED)


                                                                             
INVESTMENT INCOME:
Interest                                                                        $  5,861,400
Dividends                                                                             34,953
Other                                                                                 21,909
                                                                                ------------
        TOTAL INVESTMENT INCOME                                                    5,918,262
                                                                                ------------

EXPENSES:
Investment advisory fees                                                             509,779
Interest                                                                             348,000
Trustees' fees and expenses                                                           89,153
Professional fees                                                                     69,000
Reports to shareholders                                                               56,000
Custodian fees                                                                        12,000
Transfer agent/registrar's expenses                                                    9,000
Other                                                                                 19,650
                                                                                ------------
        TOTAL EXPENSES                                                             1,112,582
                                                                                ------------
INVESTMENT INCOME - NET                                                            4,805,680
                                                                                ------------

NET REALIZED AND UNREALIZED GAIN (LOSS) ON INVESTMENTS:
Net realized gain on investments before taxes                                        875,185
Income tax expense                                                                      (504)
                                                                                ------------
      Net realized gain on investments after taxes                                   874,681
Net change in unrealized depreciation of investments before taxes                  2,394,046
Net change in deferred income tax expense                                              8,755
                                                                                ------------
Net change in unrealized depreciation of investments after taxes                   2,402,801
                                                                                ------------
        NET GAIN ON INVESTMENTS                                                    3,277,482
                                                                                ------------
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS                            $  8,083,162
                                                                                ============

See Notes to Consolidated Financial Statements
--------------------------------------------------------------------------------
                                                                               3

CONSOLIDATED STATEMENT OF CASH FLOWS
FOR THE SIX MONTHS ENDED JUNE 30, 2010
(UNAUDITED)


                                                                             
NET DECREASE IN CASH:
Cash flows from operating activities:
   Purchases/Proceeds/Maturities from short-term portfolio securities, net      $  6,276,604
   Purchases of portfolio securities                                             (15,361,797)
   Proceeds from disposition of portfolio securities                               8,718,138
   Interest, dividends and other income received                                   4,262,140
   Interest expense paid                                                            (348,000)
   Operating expenses paid                                                          (797,323)
   Income taxes paid                                                                 (36,504)
                                                                                ------------
        NET CASH PROVIDED BY OPERATING ACTIVITIES                                  2,713,258
                                                                                ------------

Cash flows from financing activities:
   Cash dividends paid from net investment income                                 (4,996,034)
   Receipts for shares issued on reinvestment of dividends                           421,142
                                                                                ------------
        NET CASH USED FOR FINANCING ACTIVITIES                                    (4,574,892)
                                                                                ------------

NET DECREASE IN CASH                                                              (1,861,634)
Cash - beginning of year                                                           3,281,242
                                                                                ------------
CASH - END OF PERIOD                                                            $  1,419,608
                                                                                ============

RECONCILIATION OF NET INCREASE IN NET ASSETS TO NET
CASH PROVIDED BY OPERATING ACTIVITIES:

NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS                            $  8,083,162
                                                                                ------------

   Increase in investments                                                        (3,749,914)
   Increase in interest receivable                                                (1,419,987)
   Increase in receivable for investments sold                                       (97,369)
   Increase in other assets                                                          (12,569)
   Increase in investment advisory fee payable                                        13,509
   Decrease in accrued expenses                                                      (26,631)
   Decrease in accrued taxes payable                                                 (44,755)
   Decrease in other payables                                                        (32,188)

        TOTAL ADJUSTMENTS TO NET ASSETS FROM OPERATIONS                           (5,369,904)
                                                                                ------------
        NET CASH PROVIDED BY OPERATING ACTIVITIES                               $  2,713,258
                                                                                ============


See Notes to Consolidated Financial Statements
--------------------------------------------------------------------------------
4

                                              MassMutual Participation Investors

CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS


                                                                           For the six
                                                                           months ended     For the
                                                                            06/30/10       year ended
                                                                           (Unaudited)      12/31/09
                                                                           -----------    -----------
                                                                                    
INCREASE (DECREASE) IN NET ASSETS:

Operations:
   Investment income - net                                                 $  4,805,680   $  9,375,528
   Net realized gain on investments                                             874,681      1,012,575
   Net change in unrealized depreciation of investments                       2,402,801     (2,299,878)
                                                                            -----------    -----------
   Net increase in net assets resulting from operations                       8,083,162      8,088,225


Increase from common shares issued on reinvestment of dividends
   Common shares issued (2010 - 35,405; 2009 - 55,996)                          421,142        616,488

Dividends to shareholders from:
   Net investment income (2010 - $0.25 per share; 2009 - $1.00 per share)    (2,500,224)    (9,955,268)
                                                                            -----------    -----------

TOTAL INCREASE (DECREASE) IN NET ASSETS                                       6,004,080     (1,250,555)

NET ASSETS, BEGINNING OF YEAR                                               108,925,375    110,175,930
                                                                            -----------    -----------

NET ASSETS, END OF PERIOD/YEAR (including undistributed net investment
   income of $3,577,580 and $1,272,124, respectively)                      $114,929,455   $108,925,375
                                                                           ============   ============

See Notes to Consolidated Financial Statements
--------------------------------------------------------------------------------
                                                                               5

CONSOLIDATED SELECTED FINANCIAL HIGHLIGHTS
SELECTED DATA FOR EACH SHARE OF BENEFICIAL INTEREST OUTSTANDING:


                                           For the six months              For the years ended December 31,
                                            ended 06/30/2010   --------------------------------------------------------
                                               (Unaudited)       2009        2008        2007        2006        2005
                                                ---------      --------    --------    --------    --------    --------
                                                                                             
Net asset value:
   Beginning of year                            $ 10.91       $ 11.10      $ 12.84     $ 12.90     $ 12.21     $ 11.13
Net investment income (a)                          0.48          0.94         1.08        1.23        1.10        0.99
Net realized and unrealized
  gain (loss) on investments                       0.33         (0.13)       (1.82)      (0.05)       0.77        1.09(b)
Total from investment operations                   0.81          0.81        (0.74)       1.18        1.87        2.08
Dividends from net investment
  income to common shareholders                   (0.25)        (1.00)       (1.00)      (1.23)      (1.18)      (1.01)
Dividends from net realized gain
  on investments to common shareholders             --            --           --        (0.02)      (0.01)        --
Increase from dividends reinvested                 0.00(c)       0.00(c)      0.00(c)     0.01        0.01        0.01
Total dividends                                   (0.25)        (1.00)       (1.00)      (1.24)      (1.18)      (1.00)
  Net asset value: end of period/year           $ 11.47       $ 10.91      $ 11.10     $ 12.84     $ 12.90     $ 12.21
Per share market value:
  End of period/year                            $ 12.91       $ 12.20      $  9.05     $ 13.18     $ 14.70     $ 14.05
Total investment return
  Net asset value (d)                              7.51%         7.60%       (6.01%)      9.95%      18.64%      22.51%
  Market value                                     5.82%        40.86%      (25.36%)     (1.30%)     16.81%      17.25%
Net assets (in millions):
  End of period/year                            $114.93       $108.93      $110.18     $126.63     $126.52     $119.02
Ratio of operating expenses
  to average net assets                            1.39%(e)      1.41%        1.33%       1.36%       1.17%       1.45%
Ratio of interest expense
  to average net assets                            0.63%(e)      0.63%        0.58%       0.56%       0.57%       0.80%
Ratio of income tax expense
  to average net assets (f)                        0.00%(e)      0.00%        0.00%       0.48%       2.68%       2.83%
Ratio of total expenses before custodian fee
  reduction to average net assets (f)              2.02%(e)      2.04%        1.91%       2.40%       4.46%       5.12%
Ratio of net expenses after custodian fee
  reduction to average net assets (f)              2.02%(e)      2.04%        1.91%       2.40%       4.42%       5.08%
Ratio of net investment income
  to average net assets                            8.72%(e)      8.55%        8.74%       9.32%       8.43%       8.45%
Portfolio turnover                                    8%           23%          32%         33%         34%         32%

(a) Calculated using average shares.
(b) Amount includes $0.10 per share in litigation proceeds.
(c) Rounds to less than $0.01 per share.
(d) Net asset value return represents portfolio returns based on change in the Trust's net asset value assuming the reinvestment of
    all dividends and distributions which differs from the total investment return based on the Trust's market value due to the
    difference between the Trust's net asset value and the market value of its shares outstanding; past performance is no guarantee
    of future results.
(e) Annualized
(f) As additional information, this ratio is included to reflect the taxes paid on retained long-term gains. These taxes paid are
    netted against realized capital gains in the Statement of Operations. The taxes paid are treated as deemed distributions and a
    credit for the taxes paid is passed on to shareholders.

Senior borrowings:
Total principal amount (in millions)            $    12       $    12      $    12     $    12     $    12     $    12
Asset coverage per $1,000 of indebtedness       $10,577       $10,077      $10,181     $11,552     $11,543     $10,918

See Notes to Consolidated Financial Statements
--------------------------------------------------------------------------------
6

                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES - 90.31%: (A)                              PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
Private Placement Investments - 86.70%

A E COMPANY, INC.
A designer and manufacturer of machined parts and assembly structures for the commercial and military aerospace industries.
11% Senior Secured Note due 2015                                         $     807,692          *   $     791,538   $     815,920
13% Senior Subordinated Note due 2016                                    $     807,693   11/10/09         722,973         818,164
Common Stock (B)                                                          184,615 shs.   11/10/09         184,615         175,384
Warrant, exercisable until 2019, to purchase
  common stock at $.01 per share (B)                                       92,308 shs.   11/10/09          68,566             923
                                                                                                    -------------   -------------
* 11/10/09 and 11/18/09.                                                                                1,767,692       1,810,391
                                                                                                    -------------   -------------
A H C HOLDING COMPANY, INC.
A designer and manufacturer of boilers and water heaters for the commercial sector.
15% Senior Subordinated Note due 2015                                    $   1,322,210   11/21/07       1,305,074       1,345,559
Limited Partnership Interest (B)                                           12.26% int.   11/21/07         119,009         174,358
                                                                                                    -------------   -------------
                                                                                                        1,424,083       1,519,917
                                                                                                    -------------   -------------
A S A P INDUSTRIES LLC
A designer and manufacturer of components used on oil and natural gas wells.
12.5% Senior Subordinated Note due 2015                                  $     450,500   12/31/08         391,316         459,510
Limited Liability Company Unit Class A-2 (B)                                  677 uts.   12/31/08          74,333          92,220
Limited Liability Company Unit Class A-3 (B)                                  608 uts.   12/31/08          66,899          82,998
                                                                                                    -------------   -------------
                                                                                                          532,548         634,728
                                                                                                    -------------   -------------
A S C GROUP, INC.
A designer and manufacturer of high reliability encryption equipment, communications products, computing systems and electronic
components primarily for the military and aerospace sectors.
12.75% Senior Subordinated Note due 2016                                 $   1,227,273   10/09/09       1,051,875       1,255,214
Limited Liability Company Unit Class A (B)                                  1,249 uts.   10/09/09         122,727         116,595
Limited Liability Company Unit Class B (B)                                  1,473 uts.   10/09/09         144,716              15
                                                                                                    -------------   -------------
                                                                                                        1,319,318       1,371,824
                                                                                                    -------------   -------------
A W X HOLDINGS CORPORATION
A provider of aerial equipment rental, sales and repair services to non-residential construction and maintenance contractors
operating in the State of Indiana.
10.5% Senior Secured Term Note due 2014                                  $     420,000   05/15/08         411,600         391,033
13% Senior Subordinated Note due 2015                                    $     420,000   05/15/08         383,659         374,704
Common Stock (B)                                                           60,000 shs.   05/15/08          60,000            --
Warrant, exercisable until 2015, to purchase
  common stock at $.01 per share (B)                                       21,099 shs.   05/15/08          35,654            --
                                                                                                    -------------   -------------
                                                                                                          890,913         765,737
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                7


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
ADVANCED TECHNOLOGIES HOLDINGS
A provider of factory maintenance services to industrial companies.
15% Senior Subordinated Note due 2013                                    $   1,164,174   12/27/07   $   1,141,642   $   1,166,957
Preferred Stock (B)                                                           546 shs.   12/27/07         270,000         224,414
                                                                                                    -------------   -------------
                                                                                                        1,411,642       1,391,371
                                                                                                    -------------   -------------
AERO HOLDINGS, INC.
A provider of geospatial services to corporate and government clients.
10.5% Senior Secured Term Note due 2014                                  $     930,000   03/09/07         916,050         942,580
14% Senior Subordinated Note due 2015                                    $     720,000   03/09/07         661,704         720,000
Common Stock (B)                                                          150,000 shs.   03/09/07         150,000           8,546
Warrant, exercisable until 2015, to purchase
  common stock at $.01 per share (B)                                       37,780 shs.   03/09/07          63,730           2,153
                                                                                                    -------------   -------------
                                                                                                        1,791,484       1,673,279
                                                                                                    -------------   -------------
ALL CURRENT HOLDING COMPANY
A specialty re-seller of essential electrical parts and components primarily serving wholesale distributors.
12% Senior Subordinated Note due 2015                                    $     603,697   09/26/08         556,199         596,849
Common Stock (B)                                                              713 shs.   09/26/08          71,303          41,504
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                          507 shs.   09/26/08          46,584          29,513
                                                                                                    -------------   -------------
                                                                                                          674,086         667,866
                                                                                                    -------------   -------------
AMERICAN HOSPICE MANAGEMENT HOLDING LLC
A for-profit hospice care provider in the United States.
12% Senior Subordinated Note due 2013                                    $   1,687,503          *       1,606,040       1,687,503
Preferred Class A Unit (B)                                                  1,706 uts.         **         170,600         280,495
Preferred Class B Unit (B)                                                    808 uts.   06/09/08          80,789         110,601
Common Class B Unit (B)                                                    16,100 uts.   01/22/04               1          49,535
Common Class D Unit (B)                                                     3,690 uts.   09/12/06            --            11,353
                                                                                                    -------------   -------------
* 01/22/04 and 06/09/08. ** 01/22/04 and 09/12/06.                                                      1,857,430       2,139,487
                                                                                                    -------------   -------------
APEX ANALYTIX HOLDING CORPORATION
A provider of audit recovery and fraud detection services and software to commercial and retail businesses in the U.S. and Europe.
12.5% Senior Subordinated Note due 2016                                  $   1,012,500   04/28/09         855,082       1,032,750
Preferred Stock Series B (B)                                                1,623 shs.   04/28/09         162,269         187,115
Common Stock (B)                                                              723 shs.   04/28/09             723          83,395
                                                                                                    -------------   -------------
                                                                                                        1,018,074       1,303,260
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
8


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
ARROW TRU-LINE HOLDINGS, INC.
A manufacturer of hardware for residential and commercial overhead garage doors in North America.
12% Senior Subordinated Note due 2012                                    $     984,209   05/18/05   $     882,714   $     836,577
Preferred Stock (B)                                                            33 shs.   10/16/09          33,224          16,610
Common Stock (B)                                                              263 shs.   05/18/05         263,298            --
Warrant, exercisable until 2012, to purchase
  common stock at $.01 per share (B)                                           69 shs.   05/18/05          59,362            --
                                                                                                    -------------   -------------
                                                                                                        1,238,598         853,187
                                                                                                    -------------   -------------
BRAVO SPORTS HOLDING CORPORATION
A designer and marketer of niche branded consumer products including canopies, trampolines, in-line skates, skateboards, and
urethane wheels.
12.5% Senior Subordinated Note due 2014                                  $   1,207,902   06/30/06       1,152,964       1,207,902
Preferred Stock Class A (B)                                                   465 shs.   06/30/06         141,946          82,820
Common Stock (B)                                                                 1 sh.   06/30/06             152            --
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                          164 shs.   06/30/06          48,760          29,106
                                                                                                    -------------   -------------
                                                                                                        1,343,822       1,319,828
                                                                                                    -------------   -------------
C D N T, INC.
A value-added converter and distributor of specialty pressure sensitive adhesives, foams, films, and foils.
10.5% Senior Secured Term Note due 2014                                  $     429,070   08/07/08         420,489         402,755
12.5% Senior Subordinated Note due 2015                                  $     429,070   08/07/08         394,529         383,292
Common Stock (B)                                                           41,860 shs.   08/07/08          41,860            --
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                       32,914 shs.   08/07/08          32,965            --
                                                                                                    -------------   -------------
                                                                                                          889,843         786,047
                                                                                                    -------------   -------------
CAPITAL SPECIALTY PLASTICS, INC.
A producer of desiccant strips used for packaging pharmaceutical products.
Common Stock (B)                                                               55 shs.          *             252         563,288
                                                                                                    -------------   -------------
*12/30/97 and 05/29/99.

CLOUGH, HARBOUR AND ASSOCIATES
An engineering service firm that is located in Albany, NY.
12.25% Senior Subordinated Note due 2015                                 $   1,270,588   12/02/08       1,177,994       1,296,000
Preferred Stock (B)                                                           147 shs.   12/02/08         146,594         178,576
                                                                                                    -------------   -------------
                                                                                                        1,324,588       1,474,576
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                9


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
COEUR, INC.
A producer of proprietary, disposable power injection syringes.
12% Senior Subordinated Note due 2016                                    $     642,857   10/10/08   $     581,786   $     655,714
Common Stock (B)                                                              321 shs.   10/10/08          32,143          20,699
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                          495 shs.   10/10/08          48,214          31,844
                                                                                                    -------------   -------------
                                                                                                          662,143         708,257
                                                                                                    -------------   -------------
CONNECTICUT ELECTRIC, INC.
A supplier and distributor of electrical products sold into the retail and wholesale markets.
10% Senior Subordinated Note due 2014 (D)                                $     771,051   01/12/07         719,275         462,631
Limited Liability Company Unit Class A (B)                                 82,613 uts.   01/12/07          82,613            --
Limited Liability Company Unit Class C (B)                                 59,756 uts.   01/12/07          59,756            --
Limited Liability Company Unit Class D (B)                                671,525 uts.   05/03/10            --              --
Limited Liability Company Unit Class E (B)                                  1,102 uts.   05/03/10            --              --
                                                                                                    -------------   -------------
                                                                                                          861,644         462,631
                                                                                                    -------------   -------------
CONNOR SPORT COURT INTERNATIONAL, INC.
A designer and manufacturer of outdoor and indoor synthetic sports flooring and other temporary flooring products.
Preferred Stock Series B-2 (B)                                              9,081 shs.   07/05/07         370,796         908,072
Preferred Stock Series C (B)                                                4,757 shs.   07/05/07         158,912         475,708
Common Stock (B)                                                              380 shs.   07/05/07               4             133
Limited Partnership Interest (B)                                            6.88% int.          *         103,135            --
                                                                                                    -------------   -------------
*08/12/04 and 01/14/05.                                                                                   632,847       1,383,913
                                                                                                    -------------   -------------
COREPHARMA LLC
A manufacturer of oral dose generic pharmaceuticals targeted at niche applications.
12% Senior Subordinated Note due 2013                                    $   1,350,000   08/04/05       1,309,431       1,350,000
Warrant, exercisable until 2013, to purchase
  common stock at $.001 per share (B)                                          10 shs.   08/04/05          72,617          99,306
                                                                                                    -------------   -------------
                                                                                                        1,382,048       1,449,306
                                                                                                    -------------   -------------
CRANE RENTAL CORPORATION
A crane rental company.
13% Senior Subordinated Note due 2015                                    $   1,215,000   08/21/08       1,106,820       1,237,196
Common Stock (B)                                                          135,000 shs.   08/21/08         135,000           5,826
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                       72,037 shs.   08/21/08         103,143           3,109
                                                                                                    -------------   -------------
                                                                                                        1,344,963       1,246,131
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
10


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
CUSTOM ENGINEERED WHEELS, INC.
A manufacturer of custom engineered, non-pneumatic plastic wheels and plastic tread cap tires used primarily for lawn and garden
products and wheelchairs.
12.5% Senior Subordinated Note due 2016                                  $   1,155,288   10/27/09   $   1,002,074   $   1,179,381
Preferred Stock PIK (B)                                                       156 shs.   10/27/09         156,468         148,647
Preferred Stock Series A (B)                                                  114 shs.   10/27/09         104,374               1
Common Stock (B)                                                               38 shs.   10/27/09          38,244          36,328
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                           28 shs.   10/27/09          25,735            --
                                                                                                    -------------   -------------
                                                                                                        1,326,895       1,364,357
                                                                                                    -------------   -------------
DAVIS-STANDARD LLC
A manufacturer, assembler, and installer of a broad range of capital equipment that is used in the extrusion, conversion, and
processing of plastic materials.
12% Senior Subordinated Note due 2014                                    $     978,261   10/30/06         930,711         951,572
Limited Partnership Interest (B)                                            0.97% int.   10/30/06         371,739         258,945
Warrant, exercisable until 2014, to purchase
  preferred stock at $.01 per share (B)                                        26 shs.   10/30/06          26,380          32,531
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                           18 shs.   10/30/06          18,000            --
                                                                                                    -------------   -------------
                                                                                                        1,346,830       1,243,048
                                                                                                    -------------   -------------
DIVERSCO, INC./DHI HOLDINGS, INC.
A contract provider of janitorial and equipment maintenance services and temporary production labor to industrial customers.
Membership Interests of MM/Lincap
  Diversco Investments Ltd. LLC (B)                                        13.57% int.   08/27/98         366,495            --
Preferred Stock (B)                                                         1,293 shs.   12/14/01       1,093,491       1,294,210
Warrants, exercisable until 2011, to purchase common
  stock of DHI Holdings, Inc. at $.01 per share (B)                         6,676 shs.          *         201,655         191,119
                                                                                                    -------------   -------------
*10/24/96 and 08/28/98.                                                                                 1,661,641       1,485,329
                                                                                                    -------------   -------------
DUNCAN SYSTEMS, INC.
A distributor of windshields and side glass for the recreational vehicle market.
10% Senior Secured Term Note due 2013                                    $     231,429   11/01/06         227,957         236,012
13% Senior Subordinated Note due 2014                                    $     488,572   11/01/06         449,601         488,572
Common Stock (B)                                                          102,857 shs.   11/01/06         102,857          90,967
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                       32,294 shs.   11/01/06          44,663          28,561
                                                                                                    -------------   -------------
                                                                                                          825,078         844,112
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               11


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
DWYER GROUP, INC.
A franchiser of a variety of home repair services.
Common Stock (B)                                                            3,656 shs.          *   $     365,600   $     633,831
Warrant, exercisable until 2011, to purchase
  common stock at $.01 per share (B)                                        1,077 shs.   10/30/03          98,719         186,649
                                                                                                    -------------   -------------
*10/30/03 and 01/02/04.                                                                                   464,319         820,480
                                                                                                    -------------   -------------
E S P HOLDCO, INC.
A manufacturer of power protection technology for commercial office equipment, primarily supplying the office equipment dealer
network.
14% Senior Subordinated Note due 2015                                    $   1,234,994   01/08/08       1,211,752       1,192,441
Common Stock (B)                                                              349 shs.   01/08/08         174,701          39,137
                                                                                                    -------------   -------------
                                                                                                        1,386,453       1,231,578
                                                                                                    -------------   -------------
E X C ACQUISITION CORPORATION
A manufacturer of pre-filled syringes and pump systems used for intravenous drug delivery.
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                           11 shs.   06/28/04          40,875          32,339
                                                                                                    -------------   -------------
EATEM HOLDING COMPANY
A developer and manufacturer of savory flavor systems for soups, sauces, gravies, and other products produced by food manufacturers
for retail and foodservice end products.
12.5% Senior Subordinated Note due 2018                                  $     950,000   02/01/10         823,900         957,350
Common Stock (B)                                                               50 shs.   02/01/10          50,000          47,500
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                          119 shs.   02/01/10         107,100               1
                                                                                                    -------------   -------------
                                                                                                          981,000       1,004,851
                                                                                                    -------------   -------------
F C X HOLDINGS CORPORATION
A distributor of specialty/technical valves, actuators, accessories, and process instrumentation supplying a number of industrial,
high purity, and energy end markets in North America.
15% Senior Subordinated Note due 2015                                    $   1,178,146   10/06/08       1,155,017       1,200,202
Preferred Stock (B)                                                         2,298 shs.   10/06/08         229,804         106,837
Common Stock (B)                                                            1,625 shs.   10/06/08           1,625            --
                                                                                                    -------------   -------------
                                                                                                        1,386,446       1,307,039
                                                                                                    -------------   -------------
F H S HOLDINGS LLC
A national provider of customized disease management services to large self-insured employers.
12% Senior Subordinated Note due 2014 (D)                                $   1,265,625   06/01/06       1,175,533            --
Limited Liability Company Units of Linden/FHS Holdings LLC (B)                 84 uts.   06/01/06          84,368            --
Common Unit Class B (B)                                                       734 uts.   06/01/06          64,779            --
                                                                                                    -------------   -------------
                                                                                                        1,324,680            --
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
12


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
FLUTES, INC.
An independent manufacturer of micro fluted corrugated sheet material for the food and consumer products packaging industries.
10% Senior Secured Term Note due 2013 (D)                                $     524,791   04/13/06   $     516,919   $     131,198
14% Senior Subordinated Note due 2014 (D)                                $     317,177   04/13/06         283,220            --
                                                                                                    -------------   -------------
                                                                                                          800,139         131,198
                                                                                                    -------------   -------------
GOLDEN COUNTY FOODS HOLDING, INC.
A manufacturer of frozen appetizers and snacks.
16% Senior Subordinated Note due 2015                                    $   1,012,500   11/01/07         914,607         961,875
16% PIK Note due 2015                                                    $     230,898   12/31/08         223,202         219,353
8% Series A Convertible Preferred Stock, convertible into
  fully diluted common shares (B)                                          77,643 shs.   11/01/07          77,643          28,015
                                                                                                    -------------   -------------
                                                                                                        1,215,452       1,209,243
                                                                                                    -------------   -------------
H M HOLDING COMPANY
A designer, manufacturer, and importer of promotional and wood furniture.
7.5% Senior Subordinated Note due 2013 (D)                               $     362,700   10/15/09         271,181         272,025
Preferred Stock (B)                                                            21 shs.          *          21,428            --
Preferred Stock Series B (B)                                                1,088 shs.   10/15/09         813,544            --
Common Stock (B)                                                              180 shs.   02/10/06         180,000            --
Common Stock Class C (B)                                                      296 shs.   10/15/09            --              --
Warrant, exercisable until 2013, to purchase
  common stock at $.02 per share (B)                                           67 shs.   02/10/06          61,875            --
                                                                                                    -------------   -------------
* 09/18/07 and 06/27/08.                                                                                1,348,028         272,025
                                                                                                    -------------   -------------
HIGHGATE CAPITAL LLC
An acquirer of controlling or substantial interests in manufacturing and marketing entities.
Series A Preferred Units (B)                                                0.30% int.   07/21/94          91,867            --
                                                                                                    -------------   -------------
HOME DECOR HOLDING COMPANY
A designer, manufacturer and marketer of framed art and wall decor products.
12.5% Senior Subordinated Note due 2012                                  $   1,081,731          *       1,017,527       1,081,731
Common Stock (B)                                                               33 shs.          *          33,216          46,673
Warrant, exercisable until 2012, to purchase
  common stock at $.02 per share (B)                                          106 shs.          *         105,618         148,392
                                                                                                    -------------   -------------
* 06/30/04 and 08/19/04.                                                                                1,156,361       1,276,796
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               13


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
HOSPITALITY MINTS HOLDING COMPANY
A manufacturer of individually-wrapped imprinted promotional mints.
12% Senior Subordinated Note due 2016                                    $   1,098,837   08/19/08   $   1,016,628   $   1,043,895
Common Stock (B)                                                              251 shs.   08/19/08         251,163          44,165
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                           65 shs.   08/19/08          60,233          11,416
                                                                                                    -------------   -------------
                                                                                                        1,328,024       1,099,476
                                                                                                    -------------   -------------
INSURANCE CLAIMS MANAGEMENT, INC.
A third party administrator providing auto and property claim administration services for insurance companies.
Common Stock (B)                                                               37 shs.   02/27/07           1,100         117,434
Warrant, exercisable until 2011, to purchase
  common stock at $.01 per share (B)                                           11 shs.   02/27/07             324          34,594
                                                                                                    -------------   -------------
                                                                                                            1,424         152,028
                                                                                                    -------------   -------------
INTERNATIONAL OFFSHORE SERVICES LLC
A leading provider of marine transportation services, platform decomissioning, and salvage services to oil and gas producers in
the shallow waters of the Gulf of Mexico.
14.25% Senior Subordinated Secured Note due 2017                         $   1,350,000   07/07/09       1,217,417       1,366,575
Limited Liability Company Unit (B)                                          1,647 uts.   07/07/09          98,833              16
                                                                                                    -------------   -------------
                                                                                                        1,316,250       1,366,591
                                                                                                    -------------   -------------
JASON, INC.
A diversified manufacturing company serving various industrial markets.
13% Senior Subordinated Note due 2010 (D)                                $     510,187   08/04/00         449,086          25,509
Limited Partnership Interest of
Saw Mill Capital Fund II, L.P. (B)                                          1.30% int.   08/03/00         469,312            --
Warrant, exercisable until 2010, to purchase
  common stock at $.01 per share (B)                                       26,931 shs.   08/04/00          61,101            --
                                                                                                    -------------   -------------
                                                                                                          979,499          25,509
                                                                                                    -------------   -------------
JUSTRITE MANUFACTURING ACQUISITION CO.
A manufacturer of safety products such as storage cabinets and containers.
12% Senior Subordinated Note due 2011                                    $     843,750   12/15/04         825,790         843,750
Warrant, exercisable until 2011, to purchase
  common stock at $.01 per share (B)                                          594 shs.   12/15/04          53,528         107,129
                                                                                                    -------------   -------------
                                                                                                          879,318         950,879
                                                                                                    -------------   -------------
K H O F HOLDINGS, INC.
A manufacturer of premium disposable tableware products serving both the foodservice and consumer channels.
Common Stock (B)                                                          116,827 shs.   10/15/07          71,515         143,263
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
14


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
K N B HOLDINGS CORPORATION
A designer, manufacturer and marketer of products for the custom framing market.
15.5% Senior Subordinated Note due 2013 (D)                              $   1,595,057   05/25/06   $   1,398,385   $   1,196,293
Common Stock (B)                                                           71,053 shs.   05/25/06          71,053            --
Warrant, exercisable until 2013, to purchase
  common stock at $.01 per share (B)                                       43,600 shs.   05/25/06          37,871            --
                                                                                                    -------------   -------------
                                                                                                        1,507,309       1,196,293
                                                                                                    -------------   -------------
K P I HOLDINGS, INC.
Pace Industries is the largest player in the U.S. non-automotive, non-ferrous die casting segment.
13% Senior Subordinated Note due 2014 (D)                                $   1,115,217   07/16/08       1,042,077         947,934
Convertible Preferred Stock Series C (B)                                       29 shs.   06/30/09          29,348            --
Convertible Preferred Stock Series D (B)                                       13 shs.   09/17/09          12,958            --
Common Stock (B)                                                              235 shs.   07/15/08         234,783            --
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                          388 shs.          *          50,836            --
                                                                                                    -------------   -------------
* 07/16/08 and 09/17/09.                                                                                1,370,002         947,934
                                                                                                    -------------   -------------
K W P I HOLDINGS CORPORATION
A manufacturer and distributor of vinyl windows and patio doors throughout the northwestern United States.
18% Senior Subordinated Note due 2014                                    $   1,555,404   03/14/07       1,411,930       1,244,323
Common Stock (B)                                                              123 shs.   03/13/07         123,000            --
Warrant, exercisable until 2019, to purchase
  preferred stock at $.01 per share (B)                                        71 shs.   07/07/09            --              --
Warrant, exercisable until 2017, to purchase
  common stock at $.01 per share (B)                                           89 shs.   03/14/07          85,890            --
                                                                                                    -------------   -------------
                                                                                                        1,620,820       1,244,323
                                                                                                    -------------   -------------
K-TEK HOLDING CORPORATION
A manufacturer of instrumentation for liquid and bulk solids level detection for process and storage tanks.
14% Senior Subordinated Note due 2015                                    $   1,211,004   12/20/07       1,189,105       1,223,114
Preferred Stock (B)                                                       192,314 shs.   12/20/07         192,314         234,958
Common Stock (B)                                                           54,326 shs.   12/20/07             543         158,889
                                                                                                    -------------   -------------
                                                                                                        1,381,962       1,616,961
                                                                                                    -------------   -------------
L H D EUROPE HOLDINGS, INC.
A non-carbonated beverage dispensing company focused on the foodservice industry.
Common Stock (B)                                                               45 shs.   12/28/09           4,191          12,825
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               15


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
M V I HOLDING, INC.
A manufacturer of large precision machined metal components used in equipment which services a variety of industries, including
the oil and gas, mining, and defense markets.
13% Senior Subordinated Note due 2016                                    $     654,518   09/12/08   $     606,708   $     622,315
Common Stock (B)                                                               32 shs.   09/12/08          32,143            --
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                           35 shs.   09/12/08          34,714            --
                                                                                                    -------------   -------------
                                                                                                          673,565         622,315
                                                                                                    -------------   -------------
MAIL COMMUNICATIONS GROUP, INC.
A provider of mail processing and handling services, lettershop services, and commercial printing services.
12.5% Senior Subordinated Note due 2014                                  $     516,177   05/04/07         483,072         516,177
Limited Liability Company Unit (B)                                         12,763 uts.          *         166,481         176,190
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                        1,787 shs.   05/04/07          22,781          24,668
                                                                                                    -------------   -------------
* 05/04/07 and 01/02/08.                                                                                  672,334         717,035
                                                                                                    -------------   -------------
MANHATTAN BEACHWEAR HOLDING COMPANY
A designer and distributor of women's swimwear.
12.5% Senior Subordinated Note due 2018                                  $     882,353   01/15/10         773,415         894,308
Common Stock (B)                                                              118 shs.   01/15/10         117,647         111,768
Warrant, exercisable until 2019, to purchase
  common stock at $.01 per share (B)                                          104 shs.   01/15/10          94,579               1
                                                                                                    -------------   -------------
                                                                                                          985,641       1,006,077
                                                                                                    -------------   -------------
MAVERICK ACQUISITION COMPANY
A manufacturer of capsules that cover the cork and neck of wine bottles.
7.03% Senior Secured Tranche A Note due 2010 (C)                         $     103,032   09/03/04         103,032         102,599
12.5% Senior Secured Tranche B Note due 2011                             $     179,104   09/03/04         173,249         175,248
6.79% Senior Secured Revolver due 2011 (C)                               $      29,105   09/03/04          29,105          28,704
Limited Partnership Interest (B)                                            4.48% int.   09/03/04          33,582           9,680
Warrant, exercisable until 2011, to purchase
  common stock at $.01 per share (B)                                          243 shs.   09/03/04          22,556           6,994
                                                                                                    -------------   -------------
                                                                                                          361,524         323,225
                                                                                                    -------------   -------------
MEDSYSTEMS HOLDINGS LLC
A manufacturer of enteral feeding products, such as feeding tubes and other products related to assisted feeding.
13% Senior Subordinated Note due 2015                                    $     619,129   08/29/08         553,854         631,511
Preferred Unit (B)                                                             66 uts.   08/29/08          66,451          75,350
Common Unit Class A (B)                                                       671 uts.   08/29/08             671          13,280
Common Unit Class B (B)                                                       250 uts.   08/29/08          63,564           4,941
                                                                                                    -------------   -------------
                                                                                                          684,540         725,082
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
16


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
MEGTEC HOLDINGS, INC.
A supplier of industrial and environmental products and services to a broad array of industries.
12% Senior Subordinated Note due 2016                                    $   1,144,068   09/24/08   $   1,048,910   $   1,086,865
Preferred Stock (B)                                                            56 shs.   09/24/08          54,040            --
Limited Partnership Interest (B)                                            0.74% int.   09/16/08         205,932            --
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                           18 shs.   09/24/08          18,237            --
                                                                                                    -------------   -------------
                                                                                                        1,327,119       1,086,865
                                                                                                    -------------   -------------
MICROGROUP, INC.
A manufacturer of precision parts and assemblies, and a value-added supplier of metal tubing and bars.
12% Senior Subordinated Note due 2013 (D)                                $   1,421,795          *       1,370,596       1,208,526
Common Stock (B)                                                              238 shs.          *         238,000            --
Warrant, exercisable until 2013, to purchase
  common stock at $.02 per share (B)                                           87 shs.          *          86,281            --
                                                                                                    -------------   -------------
* 08/12/05 and 09/11/06.                                                                                1,694,877       1,208,526
                                                                                                    -------------   -------------
MILWAUKEE GEAR COMPANY
A manufacturer of high-precision custom gears and gear drives used by original equipment manufacturers operating in a number of
industries.
13% Senior Subordinated Note due 2014                                    $   1,246,154   07/21/08       1,182,295       1,121,539
Preferred Stock (B)                                                           139 shs.   07/21/08         138,374            --
Common Stock (B)                                                                9 shs.   07/21/08          10,000            --
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                            6 shs.   07/21/08           5,510            --
                                                                                                    -------------   -------------
                                                                                                        1,336,179       1,121,539
                                                                                                    -------------   -------------
MOMENTUM HOLDING CO.
A designer and supplier of upholstery fabric to commercial furniture manufacturers and architectural and design firms.
Limited Partnership Interest (B)                                           11.24% int.   08/04/06          56,198         129,076
Warrant, exercisable until 2014, to purchase
  common stock at $.02 per share (B)                                          586 shs.   08/04/06          56,705         134,547
                                                                                                    -------------   -------------
                                                                                                          112,903         263,623
                                                                                                    -------------   -------------
MONESSEN HOLDING CORPORATION
A designer and manufacturer of a broad line of gas, wood, and electric hearth products and accessories.
14% Senior Subordinated Note due 2014 (D)                                $   1,350,000   07/25/08       1,277,240         675,000
14% PIK Note due 2014 (D)                                                $     419,713   07/25/08         342,435         209,856
Warrant, exercisable until 2014, to purchase
  common stock at $.02 per share (B)                                           81 shs.   03/31/06          73,125            --
                                                                                                    -------------   -------------
                                                                                                        1,692,800         884,856
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               17


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
NABCO, INC.
A producer of explosive containment vessels in the United States.
14% Senior Subordinated Note due 2014 (D)                                $     330,882   02/24/06   $     304,577   $     165,441
Limited Liability Company Unit (B)                                            437 uts.          *         436,984            --
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                           68 shs.   02/24/06          19,687            --
                                                                                                    -------------   -------------
* 02/24/06 and 06/22/07.                                                                                  761,248         165,441
                                                                                                    -------------   -------------
NAVIS GLOBAL
A designer, manufacturer, seller and servicer of finishing machinery for the knit and woven segments of the global textile industry.
10.75% Senior Secured Note due 2011 (D)                                  $     348,118   05/28/04         347,086         330,712
14% Senior Subordinated Note due 2014 (D)                                $     764,921   05/28/04         660,453            --
                                                                                                    -------------   -------------
                                                                                                        1,007,539         330,712
                                                                                                    -------------   -------------
NESCO HOLDINGS CORPORATION
A sales and leasing company that provides equipment to the electric utility, telecommunications, and various other industries.
12% Senior Secured Subordinated Note due 2015                            $   1,125,000   08/02/07         999,658       1,136,250
Common Stock (B)                                                          225,000 shs.   08/02/07         225,000         258,207
Warrant, exercisable until 2015, to purchase
  common stock at $.01 per share (B)                                       63,191 shs.   08/02/07         102,842          72,517
                                                                                                    -------------   -------------
                                                                                                        1,327,500       1,466,974
                                                                                                    -------------   -------------
NETSHAPE TECHNOLOGIES, INC.
A manufacturer of powder metal and metal injection molded precision components used in industrial, consumer, and other applications.
12% Senior Subordinated Note due 2014                                    $     810,000   02/02/07         745,713         613,691
Limited Partnership Interest of
  Saw Mill PCG Partners LLC (B)                                             1.38% int.   02/01/07         539,990            --
Limited Liability Company Unit Class D of
  Saw Mill PCG Partners LLC (B)                                                 8 uts.          *           8,147           4,075
Limited Liability Company Unit Class D-1 of
  Saw Mill PCG Partners LLC (B)                                                51 uts.   09/30/09          50,509          25,262
Preferred Stock Class A (B)                                                      1 sh.   12/18/08             726             360
Preferred Stock Class A-1 (B)                                                   4 shs.   09/30/09           4,383           2,190
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                           48 shs.   02/02/07          48,087            --
                                                                                                    -------------   -------------
* 12/18/08 and 09/30/09.                                                                                1,397,555         645,578
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
18


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
NORTHWEST MAILING SERVICES, INC.
A producer of promotional materials for companies that use direct mail as part of their customer retention and loyalty programs.
12% Senior Subordinated Note due 2016                                    $   1,207,895   07/09/09   $   1,013,866   $   1,244,132
Limited Partnership Interest (B)                                           1,421, uts.   07/09/09         142,105         135,000
Warrant, exercisable until 2019, to purchase
  common stock at $.01 per share (B)                                        1,852 shs.   07/09/09         185,163              19
                                                                                                    -------------   -------------
                                                                                                        1,341,134       1,379,151
                                                                                                    -------------   -------------
NYLONCRAFT, INC.
A supplier of engineered plastic components for the automotive industry.
10% Senior Secured Note due 2012                                         $     464,286   01/28/02         464,286         441,072
15% Senior Subordinated Note due 2012 (D)                                $     285,714   01/28/02         270,653         142,857
Convertible Preferred Stock A (B)                                             571 shs.   01/28/02         549,507            --
Common Stock (B)                                                          178,571 shs.   01/28/02         178,571            --
Warrant, exercisable until 2012, to purchase
  common stock at $.01 per share (B)                                      138,928 shs.   01/28/02          92,597            --
                                                                                                    -------------   -------------
                                                                                                        1,555,614         583,929
                                                                                                    -------------   -------------
O E C HOLDINGS CORPORATION
Headquartered in Dover Plains, New York, Oracle Elevator Company provides elevator maintenance, repair and modernization services.
13% Senior Subordinated Note due 2017                                    $     444,445   06/04/10         404,450         446,157
Preferred Stock Series A (B)                                                  554 shs.   06/04/10          55,354          52,586
Preferred Stock Series B (B)                                                  311 shs.   06/04/10          31,125               3
Common Stock (B)                                                              344 shs.   06/04/10             344             327
                                                                                                    -------------   -------------
                                                                                                          491,273         499,073
                                                                                                    -------------   -------------
OAKRIVER TECHNOLOGY, INC.
Designs, engineers and assembles high precision automated process equipment for the medical device industry with a focus on
defibrilators and stents.
10% Senior Secured Note due 2012                                         $      83,264   01/03/06          82,015          83,264
13% Senior Subordinated Note due 2013                                    $     392,709   01/03/06         365,328         392,709
Common Stock (B)                                                          184,176 shs.   01/03/06         184,176         131,787
Warrant, exercisable until 2013, to purchase
  common stock at $.01 per share (B)                                       43,073 shs.   01/03/06          35,900          30,821
                                                                                                    -------------   -------------
                                                                                                          667,419         638,581
                                                                                                    -------------   -------------
OLYMPIC SALES, INC.
A boat retailer in Washington state, Oregon, California and British Columbia.
12% Senior Subordinated Note due 2010 (D)                                $     511,000   08/07/98         511,000          76,650
12% Senior Subordinated Note due 2010 (D)                                $     244,154   02/09/00         213,313          36,623
                                                                                                    -------------   -------------
                                                                                                          724,313         113,273
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               19


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
ONTARIO DRIVE & GEAR LTD.
A manufacturer of all-wheel drive, off-road amphibious vehicles and related accessories.
Limited Liability Company Unit (B)                                          1,942 uts.   01/17/06   $     302,885   $     275,989
Warrant, exercisable until 2013, to purchase
  common stock at $.01 per share (B)                                          328 shs.   01/17/06          90,424          46,597
                                                                                                    -------------   -------------
                                                                                                          393,309         322,586
                                                                                                    -------------   -------------
P A S HOLDCO LLC
An independent provider of maintenance, repair and overhaul services to the aerospace gas turbine engine and airframe markets.
14% Senior Subordinated Note due 2014                                    $   1,242,817   07/03/06       1,195,300       1,255,245
Preferred Unit (B)                                                            202 uts.   07/03/06         202,320         307,684
Preferred Unit (B)                                                             36 uts.   07/03/06          36,420          55,387
Common Unit Class I (B)                                                        78 uts.   07/03/06            --           326,563
Common Unit Class L (B)                                                        17 uts.   07/03/06            --            68,989
                                                                                                    -------------   -------------
                                                                                                        1,434,040       2,013,868
                                                                                                    -------------   -------------
P I I HOLDING CORPORATION
A manufacturer of plastic film and bags for the general industrial, medical, and food industries.
12% Senior Subordinated Note due 2013                                    $   1,215,000   03/31/06       1,162,073       1,215,000
Preferred Stock (B)                                                            19 shs.   03/31/06         174,492         242,261
Common Stock (B)                                                               12 shs.   03/31/06          13,500         104,637
Warrant, exercisable until 2013, to purchase
  common stock at $.01 per share (B)                                            7 shs.   03/31/06           5,888          60,887
                                                                                                    -------------   -------------
                                                                                                        1,355,953       1,622,785
                                                                                                    -------------   -------------
PACIFIC CONSOLIDATED HOLDINGS LLC
A manufacturer of rugged, mobile liquid and gaseous oxygen and nitrogen generating systems used in the global defense, oil and gas,
and medical sectors.
14% Senior Subordinated Note due 2012                                    $     715,460   04/27/07         677,319         654,991
Limited Liability Company Unit (B)                                        928,962 uts.   04/27/07          33,477            --
                                                                                                    -------------   -------------
                                                                                                          710,796         654,991
                                                                                                    -------------   -------------
PARADIGM PACKAGING, INC.
A manufacturer of plastic bottles and closures for the nutritional, pharmaceutical, personal care, and food packaging markets.
12% Senior Subordinated Note due 2011                                    $   1,125,000   12/19/00       1,096,710       1,124,362
Membership Interests of MM/Lincap
  PPI Investments, Inc., LLC (B)                                            1.28% int.   12/21/00         140,625         145,465
                                                                                                    -------------   -------------
                                                                                                        1,237,335       1,269,827
                                                                                                    -------------   -------------
PEARLMAN ENTERPRISES, INC.
A developer and distributor of tools, equipment and supplies to the natural and engineered stone industry.
Preferred Stock Series A (B)                                                1,236 shs.   05/22/09          59,034            --
Preferred Stock Series B (B)                                                7,059 shs.   05/22/09         290,050            --
Common Stock (B)                                                           21,462 shs.   05/22/09         993,816            --
                                                                                                    -------------   -------------
                                                                                                        1,342,900            --
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
20


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
POSTLE ALUMINUM COMPANY LLC
A manufacturer and distributor of aluminum extruded products.
15% Senior Subordinated Note due 2013                                    $     810,000   06/03/10   $     793,800   $     811,904
3% Senior Subordinated PIK Note due 2014 (D)                             $   1,163,700   10/02/06       1,066,355            --
Limited Liability Company Unit Class A (B)                                    733 uts.   10/02/06         270,000            --
Limited Liability Company Unit (B)                                             76 uts.   05/22/09          38,140          36,049
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                        4,550 shs.   10/02/06          65,988            --
                                                                                                    -------------   -------------
                                                                                                        2,234,283         847,953
                                                                                                    -------------   -------------
POWER SERVICES HOLDING COMPANY
A provider of industrial motor repair services, predictive and preventative maintenance, and performance improvement consulting
serving the petrochemical, mining, power generation, metals, and paper industries.
12% Senior Subordinated Note due 2016                                    $   1,255,814   02/11/08       1,159,023       1,203,970
Limited Partnership Interest (B)                                           12.55% int.   02/11/08          94,092          11,438
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                          700 shs.   02/11/08          88,723          22,543
                                                                                                    -------------   -------------
                                                                                                        1,341,838       1,237,951
                                                                                                    -------------   -------------
PRECISION WIRE HOLDING COMPANY
A manufacturer of specialty medical wires that are used in non-elective minimally invasive surgical procedures.
14.25% Senior Subordinated Note due 2016                                 $   1,362,978   11/12/09       1,224,645       1,378,737
Warrant, exercisable until 2019, to purchase
  common stock at $.01 per share (B)                                          109 shs.   11/12/09         107,970               1
                                                                                                    -------------   -------------
                                                                                                        1,332,615       1,378,738
                                                                                                    -------------   -------------
QUALIS AUTOMOTIVE LLC
A distributor of aftermarket automotive brake and chassis products.
13% Senior Subordinated Note due 2013                                    $     922,612   05/28/04         846,452         963,554
Common Stock (B)                                                          187,500 shs.   05/28/04         187,500         273,145
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                      199,969 shs.   05/28/04         199,969         291,309
                                                                                                    -------------   -------------
                                                                                                        1,233,921       1,528,008
                                                                                                    -------------   -------------
R A J MANUFACTURING HOLDINGS LLC
A designer and manufacturer of women's swimwear sold under a variety of licensed brand names.
14.5% Senior Subordinated Note due 2014                                  $   1,288,627   12/15/06       1,188,371       1,224,196
Limited Liability Company Unit (B)                                          1,497 uts.   12/15/06         149,723          46,939
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                            2 shs.   12/15/06          69,609          22,150
                                                                                                    -------------   -------------
                                                                                                        1,407,703       1,293,285
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               21


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
R E I DELAWARE HOLDING, INC.
An engineer and manufacturer of highly complex, close tolerance components, assemblies, tooling and custom automation equipment
primarily for aerospace, medical and defense/radar markets.
12% Senior Subordinated Note due 2016                                    $   1,350,000   01/18/08   $   1,306,541   $   1,350,539
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                            3 shs.   01/18/08          16,459             248
                                                                                                    -------------   -------------
                                                                                                        1,323,000       1,350,787
                                                                                                    -------------   -------------
ROYAL BATHS MANUFACTURING COMPANY
A manufacturer and distributor of acrylic and cultured marble bathroom products.
12.5% Senior Subordinated Note due 2011                                  $     562,500   11/14/03         546,623         557,209
Warrant, exercisable until 2011, to purchase
  common stock at $.01 per share (B)                                           74 shs.   11/14/03          65,089          63,968
                                                                                                    -------------   -------------
                                                                                                          611,712         621,177
                                                                                                    -------------   -------------
SAFETY SPEED CUT MANUFACTURING COMPANY, INC.
A manufacturer of vertical panel saws and routers for the woodworking industry.
Class B Common Stock (B)                                                      846 shs.   06/02/99         146,456         156,850
                                                                                                    -------------   -------------
SAVAGE SPORTS HOLDING, INC.
A manufacturer of sporting firearms.
12% Senior Subordinated Note due 2012                                    $     814,655   09/10/04         787,459         814,655
Preferred Stock Series A (B)                                               35,038 shs.   05/28/10          35,038          33,286
Common Stock (B)                                                              324 shs.          *         340,378         553,439
Warrant, exercisable until 2012, to purchase
  common stock at $.01 per share (B)                                           71 shs.   09/10/04          60,129         120,834
                                                                                                    -------------   -------------
* 09/10/04 and 10/05/07.                                                                                1,223,004       1,522,214
                                                                                                    -------------   -------------
SENCORE HOLDING COMPANY
A designer, manufacturer, and marketer of decoders, receivers and modulators sold to broadcasters, satellite, cable and telecom
operators for encoding/decoding analog and digital transmission video signals.
12.5% Senior Subordinated Note due 2014                                  $     934,615   01/15/09         828,083         794,423
Common Stock (B)                                                               69 shs.   01/15/09          69,231           5,112
Warrant, exercisable until 2019, to purchase
  common stock at $.01 per share (B)                                          149 shs.   01/15/09         149,084          11,012
                                                                                                    -------------   -------------
                                                                                                        1,046,398         810,547
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
22


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
SMART SOURCE HOLDINGS LLC
A short-term computer rental company.
12% Senior Subordinated Note due 2015                                    $   1,176,924          *   $   1,085,925   $   1,143,796
Limited Liability Company Unit (B)                                            328 uts.          *         334,371         174,616
Warrant, exercisable until 2015, to purchase
  common stock at $.01 per share (B)                                           83 shs.          *          87,231          44,230
                                                                                                    -------------   -------------
* 08/31/07 and 03/06/08.                                                                                1,507,527       1,362,642
                                                                                                    -------------   -------------
SPARTAN FOODS HOLDING COMPANY
A manufacturer of branded pizza crusts and pancakes.
12.25% Senior Subordinated Note due 2017                                 $   1,012,500   12/15/09         876,455       1,027,226
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                          136 shs.   12/15/09         120,234               1
                                                                                                    -------------   -------------
                                                                                                          996,689       1,027,227
                                                                                                    -------------   -------------
SPECIALTY COMMODITIES, INC.
A distributor of specialty food ingredients.
13.25% Senior Subordinated Note due 2016                                 $   1,216,509   10/23/08       1,145,544       1,240,839
Common Stock (B)                                                           15,882 shs.   10/23/08         158,824         143,728
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                        5,852 shs.   10/23/08          53,285          52,959
                                                                                                    -------------   -------------
                                                                                                        1,357,653       1,437,526
                                                                                                    -------------   -------------
STANTON CARPET HOLDING CO.
A designer and marketer of high and mid-priced decorative carpets and rugs.
12.13% Senior Subordinated Note due 2014                                 $   1,185,366   08/01/06       1,129,815       1,122,735
Common Stock (B)                                                              165 shs.   08/01/06         164,634          27,957
Warrant, exercisable until 2014, to purchase
  common stock at $.02 per share (B)                                           55 shs.   08/01/06          49,390           9,311
                                                                                                    -------------   -------------
                                                                                                        1,343,839       1,160,003
                                                                                                    -------------   -------------
SUNDANCE INVESTCO LLC
A provider of post-production services to producers of movies and television shows.
Limited Liability Company Unit Class A (B)                                  3,405 shs.   03/31/10            --              --
                                                                                                    -------------   -------------
SYNTERACT HOLDINGS CORPORATION
A provider of outsourced clinical trial management services to pharmaceutical and biotechnology companies.
14.5% Senior Subordinated Note due 2016                                  $   1,376,910   09/02/08       1,292,394       1,381,316
Redeemable Preferred Stock Series A (B)                                       678 shs.   09/02/08           6,629           4,779
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                        6,778 shs.   09/02/08          59,661            --
                                                                                                    -------------   -------------
                                                                                                        1,358,684       1,386,095
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               23


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
T H I ACQUISITION, INC.
A machine servicing company providing value-added steel services to long steel products.
12% Senior Subordinated Note due 2016                                    $   1,350,000   01/14/08   $   1,276,383   $   1,080,000
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                            5 shs.   01/14/08          46,617            --
                                                                                                    -------------   -------------
                                                                                                        1,323,000       1,080,000
                                                                                                    -------------   -------------
TELECORPS HOLDINGS, INC.
A provider of equipment and services to producers of television shows and motion pictures.
12.75% Senior Subordinated Note due 2016                                 $   1,681,677          *       1,474,695       1,597,593
Common Stock (B)                                                              143 shs.   09/02/09           5,823            --
Warrant, exercisable until 2019, to purchase
  common stock at $.01 per share (B)                                        4,187 shs.          *         173,349            --
                                                                                                    -------------   -------------
* 05/20/09 and 09/02/09.                                                                                1,653,867       1,597,593
                                                                                                    -------------   -------------
TERRA RENEWAL LLC
A provider of wastewater residual management and required environmental reporting, permitting, nutrient management planning and
record keeping to companies involved in poultry and food processing.
12% Senior Subordinated Note due 2014                                    $     664,062          *         639,292         530,320
6.79% Term Note due 2012 (C)                                             $     780,658          *         777,934         725,384
8.75% Term Note due 2012 (C)                                             $         826          *             826             770
Limited Partnership Interest of
  Saw Mill Capital Fund V, LLC (B)                                          2.27% int.         **          85,245            --
Warrant, exercisable until 2016, to purchase
  common stock at $.01 per share (B)                                           41 shs.   04/28/06          33,738            --
                                                                                                    -------------   -------------
* 04/28/06 and 09/13/06. ** 03/01/05 and 10/10/08.                                                      1,537,035       1,256,474
                                                                                                    -------------   -------------
TORRENT GROUP HOLDINGS, INC.
A contractor specializing in the sales and installation of engineered drywells for the retention and filtration of stormwater
and nuisance water flow.
14.5% Senior Subordinated Note due 2013 (D)                              $   1,185,366   10/26/07       1,113,016            --
Series A Preferred Stock (B)                                                  219 shs.   10/26/07         219,203            --
                                                                                                    -------------   -------------
                                                                                                        1,332,219            --
                                                                                                    -------------   -------------
TOTAL E & S, INC.
A manufacturer of a wide variety of equipment used in the oil and gas industry.
10.5% Senior Secured Term Note due 2013                                  $     486,487   03/02/07         479,190         462,163
13% Senior Subordinated Note due 2014 (D)                                $     341,971   03/02/07         280,347         170,986
                                                                                                    -------------   -------------
                                                                                                          759,537         633,149
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
24


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
TRANSPAC HOLDING COMPANY
A designer, importer, and wholesaler of home decor and seasonal gift products.
14% Senior Subordinated Note due 2015 (D)                                $     938,651   10/31/07   $     873,498   $     891,718
Common Stock (B)                                                              110 shs.   10/31/07         110,430            --
Warrant, exercisable until 2015, to purchase
  common stock at $.01 per share (B)                                           50 shs.   10/31/07          46,380            --
                                                                                                    -------------   -------------
                                                                                                        1,030,308         891,718
                                                                                                    -------------   -------------
TRANSTAR HOLDING COMPANY
A distributor of aftermarket automotive transmission parts.
12% Senior Subordinated Note due 2014                                    $     918,000   08/31/05         892,843         927,180
Common Stock (B)                                                              571 shs.          *         570,944         802,819
Warrant, exercisable until 2013, to purchase
  common stock at $.02 per share (B)                                           46 shs.   08/31/05          41,021          63,979
                                                                                                    -------------   -------------
* 08/31/05 and 04/30/07.                                                                                1,504,808       1,793,978
                                                                                                    -------------   -------------
TRANZONIC COMPANIES (THE)
A producer of commercial and industrial supplies, such as safety products, janitorial supplies, work apparel, washroom and restroom
supplies and sanitary care products.
13% Senior Subordinated Note due 2010                                    $   1,356,000   02/05/98       1,340,791       1,356,000
Common Stock (B)                                                              315 shs.   02/04/98         315,000         373,224
Warrant, exercisable until 2010, to purchase
  common stock at $.01 per share (B)                                          222 shs.   02/05/98         184,416         263,034
                                                                                                    -------------   -------------
                                                                                                        1,840,207       1,992,258
                                                                                                    -------------   -------------
TRUCK BODIES & EQUIPMENT INTERNATIONAL
A designer and manufacturer of accessories for heavy and medium duty trucks, primarily dump bodies, hoists, various forms of
flat-bed bodies, landscape bodies and other accessories.
8% Senior Subordinated Note due 2011 (D)                                 $   1,222,698          *       1,133,973         733,619
Preferred Stock Series B (B)                                                  128 shs.   10/20/08         127,677            --
Common Stock (B)                                                              393 shs.          *         423,985            --
Warrant, exercisable until 2013, to purchase
  common stock at $.02 per share (B)                                           81 shs.          *          84,650            --
Warrant, exercisable until 2018, to purchase
  common stock at $.01 per share (B)                                          558 shs.   10/20/08            --              --
                                                                                                    -------------   -------------
* 07/19/05 and 12/22/05.                                                                                1,770,285         733,619
                                                                                                    -------------   -------------
TRUSTILE DOORS, INC.
A manufacturer and distributor of interior doors.
Warrant, exercisable until 2010, to purchase
  common stock at $.01 per share (B)                                        3,060 shs.   04/11/03          36,032          27,457
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               25


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
U M A ENTERPRISES, INC.
An importer and wholesaler of home decor products.
15% Senior Subordinated Note due 2015                                    $     945,838   02/08/08   $     925,251   $     933,068
Convertible Preferred Stock (B)                                               470 shs.   02/08/08         469,565         222,564
                                                                                                    -------------   -------------
                                                                                                        1,394,816       1,155,632
                                                                                                    -------------   -------------
U-LINE CORPORATION
A manufacturer of high-end, built-in, undercounter ice making, wine storage and refrigeration appliances.
14.5% Senior Subordinated Note due 2012                                  $     996,500   04/30/04         955,920         946,675
14.5% PIK Note due 2012                                                  $     144,168   10/06/09         123,047         136,960
Common Stock (B)                                                               96 shs.   04/30/04          96,400           7,016
Warrant, exercisable until 2012, to purchase
  common stock at $.01 per share (B)                                          122 shs.   04/30/04         112,106           8,879
                                                                                                    -------------   -------------
                                                                                                        1,287,473       1,099,530
                                                                                                    -------------   -------------
VISIONEERING, INC.
A designer and manufacturer of tooling and fixtures for the aerospace industry.
10.5% Senior Secured Term Loan due 2013                                  $     458,824   05/17/07         451,942         453,640
13% Senior Subordinated Note due 2014                                    $     370,588   05/17/07         340,367         364,335
18% PIK Convertible Preferred Stock (B)                                    21,361 shs.   03/13/09          41,440          33,152
Common Stock (B)                                                           70,588 shs.   05/17/07          70,588            --
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                       20,003 shs.   05/17/07          31,460            --
                                                                                                    -------------   -------------
                                                                                                          935,797         851,127
                                                                                                    -------------   -------------
VITEX PACKAGING GROUP, INC.
A manufacturer of specialty packaging, primarily envelopes and tags used on tea bags.
10% Senior Subordinated PIK Note due 2011                                $      87,440   10/29/09          79,886          83,071
5% Senior Subordinated PIK Note due 2011 (D)                             $     450,000   06/30/07         392,576         427,500
Class B Unit (B)                                                          406,525 uts.   10/29/09         184,266            --
Class C Unit (B)                                                          450,000 uts.   10/29/09         413,244         104,071
Limited Liability Company Unit Class A (B)                                383,011 uts.          *         229,353            --
Limited Liability Company Unit Class B (B)                                 96,848 uts.   07/19/04          96,848            --
                                                                                                    -------------   -------------
* 07/19/04 and 10/29/09.                                                                                1,396,173         614,642
                                                                                                    -------------   -------------
WAGGIN' TRAIN HOLDINGS LLC
A producer of premium quality meat dog treats.
14% Senior Subordinated Note due 2014                                    $   1,186,865   11/15/07       1,162,805       1,198,733
Limited Liability Company Unit Class B (B)                                    224 uts.   11/15/07         223,757         270,095
Limited Liability Company Unit Class C (B)                                    224 uts.   11/15/07            --           219,864
                                                                                                    -------------   -------------
                                                                                                        1,386,562       1,688,692
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
26


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                       PRINCIPAL AMOUNT,
                                                                         SHARES, UNITS,
                                                                          OR OWNERSHIP  ACQUISITION
CORPORATE RESTRICTED SECURITIES:(A)(Continued)                             PERCENTAGE      DATE         COST         FAIR VALUE
                                                                         -------------   --------   -------------   -------------
                                                                                                        
WALLS INDUSTRIES, INC.
A provider of branded workwear and sporting goods apparel.
Limited Partnership Interest (B)                                            0.20% int.   07/12/04   $       1,974   $       --
Common Stock (B)                                                            2,133 shs.   12/21/07            --             --
                                                                                                    -------------   -------------
                                                                                                            1,974           --
                                                                                                    -------------   -------------
WELLBORN FOREST HOLDING CO.
A manufacturer of semi-custom kitchen and bath cabinetry.
14.13% Senior Subordinated Note due 2014                                 $     911,250   11/30/06         858,237         865,688
Common Stock (B)                                                              101 shs.   11/30/06         101,250          15,726
Warrant, exercisable until 2014, to purchase
  common stock at $.01 per share (B)                                           51 shs.   11/30/06          45,790           7,851
                                                                                                    -------------   -------------
                                                                                                        1,005,277         889,265
                                                                                                    -------------   -------------
WHEATON HOLDING CORPORATION
A distrtibutor and manufacturer of laboratory supply products and packaging.
13% Senior Subordinated Note due 2017                                    $   1,000,000   06/08/10         909,644       1,000,000
Preferred Stock Series B (B)                                                  703 shs.   06/08/10          70,308               7
Common Stock (B)                                                              353 shs.   06/08/10             353               4
                                                                                                    -------------   -------------
                                                                                                          980,305       1,000,011
                                                                                                    -------------   -------------
WORKPLACE MEDIA HOLDING CO.
A direct marketer specializing in providing advertisers with access to consumers in the workplace.
13% Senior Subordinated Note due 2015                                    $     613,692   05/14/07         568,491         429,584
Limited Partnership Interest (B)                                           12.26% int.   05/14/07          61,308            --
Warrant, exercisable until 2015, to purchase
  common stock at $.02 per share (B)                                           47 shs.   05/14/07          44,186            --
                                                                                                    -------------   -------------
                                                                                                          673,985         429,584
                                                                                                    -------------   -------------
XALOY SUPERIOR HOLDINGS, INC.
A provider of melt processing components and ancillary equipment for both plastic injection molding and extrusion applications.
15.5% Senior Subordinated Note due 2015 (D)                              $   1,229,741   09/08/08       1,203,293         614,870
Common Stock (B)                                                              150 shs.   09/08/08         150,000            --
                                                                                                    -------------   -------------
                                                                                                        1,353,293         614,870
                                                                                                    -------------   -------------
Total Private Placement Investments (E)                                                               115,142,081      99,640,015
                                                                                                    -------------   -------------

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               27


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                                                       SHARES OR
                                                             INTEREST      DUE         PRINCIPAL                       MARKET
CORPORATE RESTRICTED SECURITIES:(A) (Continued)                RATE        DATE         AMOUNT           COST           VALUE
                                                              ------     --------    ------------    ------------    ------------
RULE 144A SECURITIES - 3.16%:
                                                                                                      
BONDS - 3.61%
Advanced Micro Devices, Inc.                                   8.125%    12/15/17    $    190,000    $    180,723    $    188,575
Appleton Papers, Inc.                                         11.250     12/15/15         252,000         250,000         207,900
ArcelorMittal                                                  6.125     06/01/18         500,000         519,681         522,940
Avis Budget Car Rental LLC                                     9.625     03/15/18          40,000          39,454          40,100
Cenveo Corporation                                            10.500     08/15/16          45,000          45,000          45,788
Coffeyville Resources LLC                                      9.000     04/01/15          70,000          69,658          69,300
Compucom Systems, Inc.                                        12.500     10/01/15         670,000         652,477         706,012
Eastman Kodak Co.                                              9.750     03/01/18         375,000         367,576         370,312
G F S I, Inc. (C)                                             10.500     06/01/11         358,000         343,948         266,710
Gannett Company, Inc.                                          9.375     11/15/17          60,000          59,149          63,450
International Lease Finance Corporation                        8.625     09/15/15          75,000          73,853          71,063
JohnsonDiversey, Inc.                                          8.250     11/15/19          45,000          44,626          46,237
L B I Escrow Corporation                                       8.000     11/01/17         100,000         100,000         103,000
Magnachip Semiconductor                                       10.500     04/15/18          95,000          95,261          95,713
NBC Universal                                                  5.150     04/30/20         500,000         499,295         521,249
Sealed Air Corporation                                         7.875     06/15/17         500,000         492,697         522,642
Sinclair Television Group, Inc.                                9.250     11/01/17         200,000         194,848         202,000
ViaSystems, Inc.                                              12.000     01/15/15         100,000          96,644         108,000
                                                                                                     ------------    ------------
  TOTAL BONDS                                                                                           4,124,890       4,150,991
                                                                                                     ------------    ------------
CONVERTIBLE PREFERRED STOCK - 0.00%
ETEX Corporation (B)                                                                          194             179            --
                                                                                                     ------------    ------------
  TOTAL CONVERTIBLE PREFERRED STOCK                                                                           179            --
                                                                                                     ------------    ------------
PREFERRED STOCK - 0.00%
TherOX, Inc. (B)                                                                               26           1,032            --
                                                                                                     ------------    ------------
  TOTAL PREFERRED STOCK                                                                                     1,032            --
                                                                                                     ------------    ------------
COMMON STOCK - 0.00%
Touchstone Health Partnership (B)                                                             292           1,062            --
                                                                                                     ------------    ------------
  TOTAL COMMON STOCK                                                                                        1,062            --
                                                                                                     ------------    ------------
  TOTAL RULE 144A SECURITIES                                                                            4,127,163       4,150,991
                                                                                                     ------------    ------------

TOTAL CORPORATE RESTRICTED SECURITIES                                                                $119,269,244    $103,791,006
                                                                                                     ------------    ------------

---------------------------------------------------------------------------------------------------------------------------------
28


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                             INTEREST      DUE         PRINCIPAL                       MARKET
CORPORATE PUBLIC SECURITIES - 15.62%: (A)                      RATE        DATE         AMOUNT           COST           VALUE
                                                              ------     --------    ------------    ------------    ------------
                                                                                                      
BONDS - 15.17%
ACCO Brands Corporation                                       10.625%    03/15/15    $     45,000    $     44,398    $     48,825
Affinia Group, Inc.                                            9.000     11/30/14          25,000          24,250          25,125
Allegheny Technologies, Inc.                                   9.375     06/12/19         500,000         521,028         590,387
Allied Waste NA                                                7.125     05/15/16         500,000         506,218         536,250
American General Finance Corporation                           6.500     09/15/17         250,000         215,000         195,000
C R H America, Inc.                                            5.300     10/15/13         500,000         418,430         537,491
Centurytel, Inc.                                               5.000     02/15/15         500,000         515,591         502,117
Citigroup, Inc.                                                5.500     04/11/13         500,000         437,890         519,751
Cytec Industries, Inc.                                         8.950     07/01/17         600,000         603,785         730,544
Equifax, Inc.                                                  4.450     12/01/14         500,000         517,378         522,084
Exide Corporation                                             10.500     03/15/13         250,000         252,465         252,500
GATX Corporation                                               4.750     05/15/15         500,000         513,163         522,779
Gencorp, Inc.                                                  9.500     08/15/13         130,000         130,000         131,463
General Electric Capital Corporation                           5.500     01/08/20         500,000         498,050         528,378
Goldman Sachs Group, Inc.                                      4.750     07/15/13         500,000         418,645         522,037
Goodyear Tire & Rubber Co.                                    10.500     05/15/16          50,000          48,163          54,375
Headwaters, Inc.                                              11.375     11/01/14          45,000          44,580          45,450
Intelsat Burmuda Ltd.                                          9.250     06/15/16         690,000         713,892         684,825
International Game Technology                                  7.500     06/15/19         500,000         499,720         580,606
International Lease Finance Corporation                        5.875     05/01/13         500,000         448,188         461,250
Iron Mountain, Inc.                                            8.750     07/15/18         500,000         512,345         516,250
Johnson Controls, Inc.                                         5.500     01/15/16         500,000         398,125         554,205
Kraft Foods, Inc.                                              5.375     02/10/20         500,000         517,040         533,918
Manitowoc Company, Inc.                                        7.125     11/01/13         100,000         100,000          96,500
Markwest Energy Operating Co.                                  6.875     11/01/14          35,000          27,789          33,600
Masco Corporation                                              7.125     03/15/20         350,000         349,993         339,703
Morgan Stanley                                                 5.500     01/26/20         500,000         497,305         483,700
Nortek, Inc.                                                  11.000     12/01/13         100,444          98,956         104,713
Owens Corning, Inc.                                            9.000     06/15/19          30,000          29,516          34,725
Qwest Diagnostic, Inc.                                         4.750     01/30/20         500,000         498,665         501,643
Rental Service Corporation                                     9.500     12/01/14         175,000         175,648         173,906
Sheridan Acquisition Corporation                              10.250     08/15/11         225,000         222,001         222,469
Sprint Capital Corporation                                     6.900     05/01/19         440,000         405,225         398,200
Stewart & Stevenson LLC                                       10.000     07/15/14         735,000         754,806         668,850
Teck Resources Ltd.                                           10.750     05/15/19          30,000          28,581          36,759
Texas Industries, Inc.                                         7.250     07/15/13          35,000          35,000          33,862
The Valspar Corporation                                        7.250     06/15/19         500,000         501,425         591,945
Ticketmaster Entertainment, Inc.                              10.750     07/28/16         250,000         250,000         269,375

---------------------------------------------------------------------------------------------------------------------------------
                                                                                                                               29


CONSOLIDATED SCHEDULE OF INVESTMENTS (CONTINUED)
June 30, 2010
(Unaudited)

                                                             INTEREST      DUE         PRINCIPAL                       MARKET
CORPORATE PUBLIC SECURITIES (A)(Continued)                     RATE        DATE         AMOUNT           COST           VALUE
                                                              ------     --------    ------------    ------------    ------------
                                                                                                      
Time Warner Cable, Inc.                                        5.000%    02/01/20    $    500,000    $    489,790    $    511,321
Titan International, Inc.                                      8.000     01/15/12          70,000          70,000          72,800
Tube City IMS Corporation                                      9.750     02/01/15       1,000,000         989,124         967,500
Tyco International Group SA                                    8.500     01/15/19         500,000         457,495         574,206
Tyco International Group SA                                    6.550     10/01/17         125,000         124,996         161,040
United Components, Inc.                                        9.375     06/15/13         535,000         535,179         537,675
Verso Paper Holdings LLC                                       9.125     08/01/14         500,000         486,875         477,500
W P P Finance Corporation                                      5.875     06/15/14         500,000         507,666         542,493
                                                                                                     ------------    ------------
  TOTAL BONDS                                                                                          16,434,379      17,430,095
                                                                                                     ------------    ------------
COMMON STOCK - 0.45%
CKX, Inc. (B)                                                                              52,500         422,625         261,975
Directed Electronics, Inc. (B)                                                            195,118         982,867         103,413
Intrepid Potash, Inc. (B)                                                                     185           5,920           3,620
ITC^DeltaCom, Inc. (B)                                                                     94,588         827,645         137,153
Nortek, Inc. (B)                                                                              100               1           4,200
Rue21, Inc. (B)                                                                               350           6,650          10,619
  TOTAL COMMON STOCK                                                                                    2,245,708         520,980
                                                                                                     ------------    ------------
TOTAL CORPORATE PUBLIC SECURITIES                                                                    $ 18,680,087    $ 17,951,075
                                                                                                     ------------    ------------

                                                             INTEREST      DUE         PRINCIPAL
SHORT-TERM SECURITIES:                                      RATE/YIELD^    DATE         AMOUNT           COST        MARKET VALUE
                                                              ------     --------    ------------    ------------    ------------
COMMERCIAL PAPER - 1.09%
Pacific Gas & Electric                                         0.380%    07/09/10    $  1,250,000    $  1,249,894    $  1,249,894
                                                                                                     ------------    ------------
  TOTAL SHORT-TERM SECURITIES                                                                        $  1,249,894    $  1,249,894
                                                                                                     ------------    ------------

TOTAL INVESTMENTS                                             107.02%                                $139,199,225    $122,991,975
                                                                                                     ============    ------------
  Other Assets                                                  3.93                                                    4,517,341
  Liabilities                                                 (10.95)                                                 (12,579,861)
                                                              ------                                                 ------------
TOTAL NET ASSETS                                              100.00%                                                $114,929,455
                                                              ======                                                 ============

(A) In each of the convertible note, warrant, and common stock investments, the issuer has agreed to provide certain registration
    rights.
(B) Non-income producing security.
(C) Variable rate security; rate indicated is as of 06/30/10.
(D) Defaulted security; interest not accrued.
(E) Illiquid security. As of June 30, 2010, the values of these securities amounted to $99,640,015 or 86.70% of net assets.
 ^  Effective yield at purchase
PIK - Payment-in-kind

---------------------------------------------------------------------------------------------------------------------------------
30


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS
June 30, 2010
(Unaudited)

                                                 Fair Value/                                                           Fair Value/
Industry Classification                         Market Value          Industry Classification                         Market Value
------------------------------------------------------------          ------------------------------------------------------------
                                                                                                             
AEROSPACE - 4.18%                                                     BUILDINGS & REAL ESTATE - 1.46%
A E Company, Inc.                               $  1,810,391          K W P I Holdings Corporation                    $  1,244,323
Gencorp, Inc.                                        131,463          Masco Corporation                                    339,703
P A S Holdco LLC                                   2,013,868          Owens Corning, Inc.                                   34,725
Visioneering, Inc.                                   851,127          Texas Industries, Inc.                                33,862
                                                ------------          TruStile Doors, Inc.                                  27,457
                                                   4,806,849                                                          ------------
                                                ------------                                                             1,680,070
AUTOMOBILE - 4.98%                                                                                                    ------------
Exide Corporation                                    252,500          CHEMICAL, PLASTICS & RUBBER - 0.49%
Goodyear Tire & Rubber Co.                            54,375          Capital Specialty Plastics, Inc.                     563,288
Jason, Inc.                                           25,509                                                          ------------
Johnson Controls, Inc.                               554,205          CONSUMER PRODUCTS - 9.93%
Nyloncraft, Inc.                                     583,929          Aero Holdings, Inc.                                1,673,279
Ontario Drive & Gear Ltd.                            322,586          Bravo Sports Holding Corporation                   1,319,828
Qualis Automotive LLC                              1,528,008          Custom Engineered Wheels, Inc.                     1,364,357
Titan International, Inc.                             72,800          Eastman Kodak Co.                                    370,312
Transtar Holding Company                           1,793,978          G F S I, Inc.                                        266,710
United Components, Inc.                              537,675          Johnson Diversey, Inc.                                46,237
                                                ------------          K N B Holdings Corporation                         1,196,293
                                                   5,725,565          Manhattan Beachwear Holding Company                1,006,077
                                                ------------          Momentum Holding Co.                                 263,623
BEVERAGE, DRUG & FOOD - 6.97%                                         R A J Manufacturing Holdings LLC                   1,293,285
Eatem Holding Company                              1,004,851          Royal Baths Manufacturing Company                    621,177
Golden County Foods Holding, Inc.                  1,209,243          The Tranzonic Companies                            1,992,258
Hospitality Mints Holding Company                  1,099,476          Walls Industries, Inc.                                  --
Kraft Foods, Inc.                                    533,918                                                          ------------
L H D Europe Holding, Inc.                            12,825                                                            11,413,436
Spartan Foods Holding Company                      1,027,227                                                          ------------
Specialty Commodities, Inc.                        1,437,526          CONTAINERS, PACKAGING & GLASS - 3.90%
Waggin' Train Holdings LLC                         1,688,692          Flutes, Inc.                                         131,198
                                                ------------          Maverick Acquisition Company                         323,225
                                                   8,013,758          P I I Holding Corporation                          1,622,785
                                                ------------          Paradigm Packaging, Inc.                           1,269,827
BROADCASTING & ENTERTAINMENT - 2.15%                                  Sealed Air Corporation                               522,642
CKX, Inc.                                            261,975          Vitex Packaging Group, Inc.                          614,642
NBC Universal                                        521,249                                                          ------------
Sinclair Television Group, Inc.                      202,000                                                             4,484,319
Time Warner Cable, Inc.                              511,321                                                          ------------
WPP Finance Corporation                              542,493          DISTRIBUTION - 1.87%
Workplace Media Holding Co.                          429,584          Duncan Systems, Inc.                                 844,112
                                                ------------          F C X Holdings Corporation                         1,307,039
                                                   2,468,622                                                          ------------
                                                ------------                                                             2,151,151
                                                                                                                      ------------
----------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                31


CONSOLIDATED SCHEDULE OF INVESTMENTS
June 30, 2010
(Unaudited)

                                                 Fair Value/                                                           Fair Value/
Industry Classification                         Market Value          Industry Classification                         Market Value
------------------------------------------------------------          ------------------------------------------------------------
                                                                                                             
DIVERSIFIED/CONGLOMERATE, MANUFACTURING - 7.98%                       ELECTRONICS - 0.49%
A H C Holdings Company, Inc.                    $  1,519,917          Connecticut Electric, Inc.                      $    462,631
Arrow Tru-Line Holdings, Inc.                        853,187          Directed Electronics, Inc.                           103,413
C D N T, Inc.                                        786,047                                                          ------------
Headwaters, Inc.                                      45,450                                                               566,044
K P I Holdings, Inc.                                 947,934                                                          ------------
MEGTEC Holdings, Inc.                              1,086,865          FINANCIAL SERVICES - 2.97%
Milwaukee Gear Company                             1,121,539          American General Finance Corporation                 195,000
Nortek, Inc.                                         108,913          Citigroup, Inc.                                      519,751
O E C Holdings Corporation                           499,073          GATX Corporation                                     522,779
Postle Aluminum Company LLC                          847,953          General Electric Capital Corporation                 528,378
Truck Bodies & Equipment International               733,619          Goldman Sachs Group, Inc.                            522,037
Xaloy Superior Holdings, Inc.                        614,870          Highgate Capital LLC                                    --
                                                ------------          International Lease Finance Corporation              532,313
                                                   9,165,367          L B I Escrow Corporation                             103,000
                                                ------------          Morgan Stanley                                       483,700
DIVERSIFIED/CONGLOMERATE, SERVICE - 13.89%                                                                            ------------
A S C Group, Inc.                                  1,371,824                                                             3,406,958
A W X Holdings Corporation                           765,737                                                          ------------
ACCO Brands Corporation                               48,825          HEALTHCARE, EDUCATION & CHILDCARE - 4.37%
Advanced Technologies Holdings                     1,391,371          American Hospice Management Holding LLC            2,139,487
Affinia Group, Inc.                                   25,125          F H S Holdings LLC                                      --
Apex Analytix Holding Corporation                  1,303,260          Qwest Diagnostic, Inc.                               501,643
C R H America, Inc.                                  537,491          Synteract Holdings Corporation                     1,386,095
Clough, Harbour and Associates                     1,474,576          Touchstone Health Partnership                           --
Crane Rental Corporation                           1,246,131          Wheaton Holdings Corporation                       1,000,011
Diversco, Inc./DHI Holdings, Inc.                  1,485,329                                                          ------------
Dwyer Group, Inc.                                    820,480                                                             5,027,236
Equifax, Inc.                                        522,084                                                          ------------
Insurance Claims Management, Inc.                    152,028          HOME & OFFICE FURNISHINGS, HOUSEWARES &
Iron Mountain, Inc.                                  516,250          DURABLE CONSUMER PRODUCTS - 8.79%
Mail Communications Group, Inc.                      717,035          Connor Sport Court International, Inc.             1,383,913
Nesco Holdings Corporation                         1,466,974          H M Holding Company                                  272,025
Northwest Mailing Services, Inc.                   1,379,151          Home Decor Holding Company                         1,276,796
Pearlman Enterprises, Inc.                              --            Justrite Manufacturing Acquisition Co.               950,879
Tyco International Group                             735,246          K H O F Holdings, Inc.                               143,263
                                                ------------          Monessen Holding Corporation                         884,856
                                                  15,958,917          Stanton Carpet Holding Co.                         1,160,003
                                                ------------          Transpac Holdings Company                            891,718
                                                                      U M A Enterprises, Inc.                            1,155,632
                                                                      U-Line Corporation                                 1,099,530
                                                                      Wellborn Forest Holding Co.                          889,265
                                                                                                                      ------------
                                                                                                                        10,107,880
                                                                                                                      ------------

----------------------------------------------------------------------------------------------------------------------------------
32


                                              MassMutual Participation Investors
CONSOLIDATED SCHEDULE OF INVESTMENTS
June 30, 2010
(Unaudited)

                                                 Fair Value/                                                           Fair Value/
Industry Classification                         Market Value          Industry Classification                         Market Value
------------------------------------------------------------          ------------------------------------------------------------
                                                                                                             
LEISURE, AMUSEMENT & ENTERTAINMENT - 2.06%                            NATURAL RESOURCES - 2.25%
International Game Technology                   $    580,606          Appleton Papers, Inc.                             $  207,900
Savage Sports Holding, Inc.                        1,522,214          ArcelorMittal                                        522,940
Ticketmaster Entertainment, Inc.                     269,375          Cenveo Corporation                                    45,788
                                                ------------          Cytec Industries, Inc.                               730,544
                                                   2,372,195          Intrepid Potash, Inc.                                  3,620
                                                ------------          The Valspar Corporation                              591,945
MACHINERY - 9.13%                                                     Verso Paper Holdings LLC                             477,500
A S A P Industries LLC                               634,728                                                          ------------
Davis-Standard LLC                                 1,243,048                                                             2,580,237
E S P Holdco, Inc.                                 1,231,578                                                          ------------
K-Tek Holdings Corporation                         1,616,961          OIL & GAS - 1.80%
M V I Holding, Inc.                                  622,315          Coffeyville Resources LLC                             69,300
Manitowoc Company, Inc.                               96,500          International Offshore Services LLC                1,366,591
Navis Global                                         330,712          Total E & S, Inc.                                    633,149
NetShape Technologies, Inc.                          645,578                                                          ------------
Pacific Consolidated Holdings LLC                    654,991                                                             2,069,040
Power Services Holding Company                     1,237,951                                                          ------------
R E I Delaware Holding, Inc.                       1,350,787          PHARMACEUTICALS - 1.26%
Safety Speed Cut Manufacturing Company, Inc.         156,850          CorePharma LLC                                     1,449,306
Stewart & Stevenson LLC                              668,850                                                          ------------
                                                ------------          PUBLISHING/PRINTING - 0.25%
                                                  10,490,849          Gannett Company, Inc.                                 63,450
                                                ------------          Sheridan Acquisition Corporation                     222,469
MEDICAL DEVICES/BIOTECH - 4.08%                                                                                       ------------
Coeur, Inc.                                          708,257                                                               285,919
E X C Acquisition Corporation                         32,339                                                          ------------
ETEX Corporation                                        --            RETAIL STORES - 0.26%
MedSystems Holdings LLC                              725,082          Olympic Sales, Inc.                                  113,273
MicroGroup, Inc.                                   1,208,526          Rental Service Corporation                           173,906
OakRiver Technology, Inc.                            638,581          Rue21, Inc.                                           10,619
Precision Wire Holding Company                     1,378,738                                                          ------------
TherOX, Inc.                                            --                                                                 297,798
                                                ------------                                                          ------------
                                                   4,691,523          TECHNOLOGY - 2.85%
                                                ------------          Advanced Micro Devices, Inc.                         188,575
MINING, STEEL, IRON                                                   Compucom Systems, Inc.                               706,012
& NON-PRECIOUS METALS - 2.33%                                         Magnachip Semiconductor                               95,713
Allegheny Technology, Inc.                           590,387          Sencore Holding Company                              810,547
T H I Acquisition, Inc.                            1,080,000          Smart Source Holdings LLC                          1,362,642
Teck Resources, Ltd.                                  36,759          ViaSystems, Inc.                                     108,000
Tube City IMS Corporation                            967,500                                                          ------------
                                                ------------                                                             3,271,489
                                                   2,674,646                                                          ------------
                                                ------------

----------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                33


CONSOLIDATED SCHEDULE OF INVESTMENTS
June 30, 2010
(Unaudited)

                                                 Fair Value/
Industry Classification                         Market Value
------------------------------------------------------------
                                             
TELECOMMUNICATIONS - 3.47%
All Current Holding Company                     $    667,866
Centurytel, Inc.                                     502,117
Intelsat Bermuda Ltd.                                684,825
ITC^DeltaCom, Inc.                                   137,153
Sprint Capital Corporation                           398,200
Sundance Investco LLC                                   --
Telecorps Holdings, Inc.                           1,597,593
                                                ------------
                                                   3,987,754
                                                ------------
TRANSPORTATION - 0.18%
Avis Budget Car Rental LLC                            40,100
NABCO, Inc.                                          165,441
                                                ------------
                                                     205,541
                                                ------------
UTILITIES - 1.12%
Markwest Energy Operating Co.                         33,600
Pacific Gas & Electric                             1,249,894
                                                ------------
                                                   1,283,494
                                                ------------
WASTE MANAGEMENT/POLLUTION - 1.56%
Allied Waste NA                                      536,250
Terra Renewal LLC                                  1,256,474
Torrent Group Holdings, Inc.                            --
                                                ------------
                                                   1,792,724
                                                ------------

Total Investments - 107.02%                     $122,991,975
                                                ============


See Notes to Consolidated Financial Statements
----------------------------------------------------------------------------------------------------------------------------------
34


                                              MassMutual Participation Investors

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
(Unaudited)

1.    HISTORY
      MassMutual  Participation  Investors  (the  "Trust")  was  organized  as a
      Massachusetts  business  trust  under  the  laws  of  the  Commonwealth of
      Massachusetts  pursuant to a Declaration of Trust dated April 7, 1988. The
      Trust  is  a  diversified closed-end management investment company. Babson
      Capital   Management  LLC  ("Babson  Capital"),  a  wholly-owned  indirect
      subsidiary  of Massachusetts Mutual Life Insurance Company ("MassMutual"),
      acts  as  its  investment  adviser. The Trust's investment objective is to
      maximize  total  return  by  providing a high level of current income, the
      potential  for  growth  of  income,  and capital appreciation. The Trust's
      principal   investments  are  privately  placed,  below-investment  grade,
      long-term  debt  obligations  purchased directly from their issuers, which
      tend  to be smaller companies. At least half of these investments normally
      include equity features such as common stock, warrants, conversion rights,
      or  other  equity  features that provide the Trust with the opportunity to
      realize  capital gains. The Trust will also invest in publicly traded debt
      securities  (including  high  yield securities), again with an emphasis on
      those  with  equity  features,  and  in  convertible preferred stocks and,
      subject  to  certain  limitations,  readily  marketable equity securities.
      Below-investment   grade  or  high  yield  securities  have  predominantly
      speculative  characteristics with respect to the capacity of the issuer to
      pay  interest  and  repay  capital. In addition, the Trust may temporarily
      invest  in  high  quality,  readily  marketable securities.

      On  January  27, 1998, the Board of Trustees authorized the formation of a
      wholly-owned  subsidiary  of  the  Trust ("MMPI Subsidiary Trust") for the
      purpose of holding certain investments. The results of the MMPI Subsidiary
      Trust  are consolidated in the accompanying financial statements. Footnote
      2.D  below  discusses  the Federal tax consequences of the MMPI Subsidiary
      Trust.

2.    SIGNIFICANT ACCOUNTING POLICIES
      The  following  is  a  summary of significant accounting policies followed
      consistently by the Trust in the preparation of its consolidated financial
      statements  in conformity with accounting principles generally accepted in
      the United States of America.

      A. VALUATION OF INVESTMENTS:
      Valuation  of  a security in the Trust's portfolio is made on the basis of
      the  market price whenever market quotations are readily available and all
      securities of the same class held by the Trust can be readily sold in such
      market.

      Nearly  all  securities  which are acquired by the Trust directly from the
      issuers  and  shares  into which such securities may be converted or which
      may  be  purchased on the exercise of warrants attached to such securities
      will  be  subject  to  legal or contractual delays in, or restrictions on,
      resale  and will therefore be "restricted securities." Generally speaking,
      as contrasted with open-market sales of unrestricted securities, which may
      be  effected  immediately if the market is adequate, restricted securities
      can  be  sold only in a public offering for which a registration statement
      is in effect under the Securities Act of 1933, as amended (the "1933 Act")
      or  pursuant  to  a transaction that is exempt from registration under the
      1933 Act.

      The  value  of  restricted  securities,  and of any other assets for which
      there  are  no reliable market quotations, is the fair value as determined
      in  good  faith  by  the  Trust's Board of Trustees (the "Trustees"). Each
      restricted  security  is  valued  by  the  Trustees  at  the  time  of its
      acquisition   and   at  least  quarterly  thereafter.  The  Trustees  have
      established   guidelines  to  aid  in  the  valuation  of  each  security.
      Generally,  restricted  securities are initially valued at cost or less at
      the time of acquisition by the Trust. Values greater or less than cost are
      used  thereafter  for  restricted securities in appropriate circumstances.
      Among  the factors ordinarily considered are the existence of restrictions
      upon  the  sale  of  a  security  held  by  the  Trust; an estimate of the
      existence  and  the extent of a market for the security; the extent of any
      discount  at which the security was acquired; the estimated period of time
      during  which  the  security  will not be freely marketable; the estimated
      expenses  of  registering  or otherwise qualifying the security for public
      sale; estimated underwriting commissions if underwriting would be required
      to effect a sale; in the case of a convertible security, whether or not it
      would  trade  on  the basis of its stock equivalent; in the case of a debt
      obligation  which  would trade independently of any equity equivalent, the
      current  yields  on  comparable  securities;  the  estimated amount of the
      floating  supply of such securities available for purchase; the proportion
      of  the  issue  held  by the Trust; changes in the financial condition and
      prospects  of  the  issuer;  the  existence  of merger proposals or tender
      offers  affecting  the issuer; and any other factors affecting fair value,
      all in accordance with the Investment Company Act of 1940, as amended (the
      "1940  Act"). In making valuations, opinions of counsel may be relied upon
      as  to  whether  or not securities are restricted securities and as to the
      legal requirements for public sale.

      When  market  quotations are readily available for unrestricted securities
      of an issuer, restricted securities of the same class are generally valued
      at  a  discount from the market price of such unrestricted securities. The
      Trustees,  however, consider all factors in fixing any discount, including
      the  filing of a registration statement for such securities under the 1933
      Act   and  any  other  developments  which  are  likely  to  increase  the
      probability  that the securities may be publicly sold by the Trust without
      restriction.

      The  Trustees  meet at least once each quarter to approve the value of the
      Trust's  portfolio  securities  as  of  the  close of business on the last
      business  day  of  the  preceding  quarter.  This  valuation  requires the
      approval  of a majority of the Trustees of the Trust, including a majority
      of  the  Trustees who are not interested persons of the Trust or of Babson
      Capital. In making valuations,
--------------------------------------------------------------------------------
                                                                              35

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
(UNAUDITED)

      the  Trustees  will  consider  reports  by  Babson  Capital analyzing each
      portfolio  security  in  accordance  with the relevant factors referred to
      above.  Babson  Capital has agreed to provide such reports to the Trust at
      least quarterly.

      The consolidated financial statements include private placement restricted
      securities  valued  at  $99,640,015  (86.70% of net assets) as of June 30,
      2010  whose  values  have been estimated by the Trustees in the absence of
      readily  ascertainable  market  values. Due to the inherent uncertainty of
      valuation, those estimated values may differ significantly from the values
      that  would  have been used had a ready market for the securities existed,
      and the differences could be material.

      The  values  for  Rule  144A  restricted  securities  and corporate public
      securities  are stated at the last reported sales price or at prices based
      upon  quotations  obtained  from  brokers and dealers as of June 30, 2010,
      subject to discount where appropriate, and are approved by the Trustees.

      Short-term  securities with more than sixty days to maturity are valued at
      fair  value  and  short-term securities having a maturity of sixty days or
      less are valued at amortized cost, which approximates market value.

      In  accordance  with the authoritative guidance on fair value measurements
      and  disclosures  under  accounting  principles  generally accepted in the
      United States of America ("U.S. GAAP"), the Trust discloses the fair value
      of its investments in a hierarchy that prioritizes the inputs to valuation
      techniques used to measure the fair value. The hierarchy gives the highest
      priority  to  valuations  based  upon  unadjusted  quoted prices in active
      markets  for identical assets or liabilities (level 1 measurement) and the
      lowest  priority  to  valuations  based  upon unobservable inputs that are
      significant   to  the  valuation  (level  3  measurements).  The  guidance
      establishes three levels of the fair value hierarchy as follows:

            Level 1: quoted prices in active markets for identical securities
            Level 2: other  significant  observable  inputs  (including quoted
                     prices for similar securities, interest rates, prepayment
                     speeds, credit risk, etc.)
            Level 3: significant unobservable inputs (including the Trust's own
                     assumptions in determining the fair value of investments)

      The inputs and methodology used for valuing securities are not necessarily
      an indication of the risk associated with investing in those securities.

      The  following  is  a  summary of the inputs used to value the Trust's net
      assets as of June 30, 2010:


ASSETS:                                     TOTAL               LEVEL 1          LEVEL 2             LEVEL 3
---------------------------------------------------------------------------------------------------------------
                                                                                       
   Restricted Securities
        Bonds                           $ 87,929,664          $     --         $ 4,150,991         $83,778,673
        Common Stock                       7,736,501                --                  --           7,736,501
        Preferred Stock                    4,447,172                --                  --           4,477,172
        Partnerships and LLCs              3,647,669                --                  --           3,647,669
   Public Securities
        Bonds                             17,430,095                --          17,430,095                  --
        Common Stock                         520,980           516,780               4,200                  --
        Preferred Stock                           --                --                  --                  --
        Short-term Securities              1,249,894                --           1,249,894                  --
---------------------------------------------------------------------------------------------------------------
TOTAL                                   $122,991,975          $516,780         $22,835,180         $99,640,015


      Following  is  a  reconciliation  of  Level 3 assets for which significant
      unobservable inputs were used to determine fair value:


                                                                                                                       UNREALIZED
                                   TOTAL GAINS        PURCHASES,                                                     GAINS & LOSSES
                                    BEGINNING         OR LOSSES    SALES, ISSUANCES   TRANSFERS         ENDING       IN NET INCOME
                                     BALANCE          (REALIZED/    & SETTLEMENTS     IN AND/OR       BALANCE AT       FROM ASSETS
ASSETS:                           AT 12/31/2009       UNREALIZED)        (NET)      OUT OF LEVEL 3    06/30/2010       STILL HELD
------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    
   Restricted Securities
        Bonds                       $81,465,949       $  977,224      $1,335,500       $      --      $83,778,673      $   26,785
        Common Stock                  7,767,378          503,842        (534,719)             --        7,736,501         300,934
        Preferred Stock               3,468,130        1,034,542         (25,500)             --        4,477,172         815,339
        Partnerships and LLCs         3,536,247           89,775          21,647              --        3,647,669          89,775
------------------------------------------------------------------------------------------------------------------------------------
                                    $96,237,704       $2,605,383      $  796,928       $      --      $99,640,015      $1,232,833

--------------------------------------------------------------------------------
36

                                              MassMutual Participation Investors

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
(UNAUDITED)

      B. ACCOUNTING FOR INVESTMENTS:
      Investment  transactions  are  accounted  for  on the trade date. Dividend
      income is recorded on the ex-dividend date. Interest income is recorded on
      the accrual basis, including the amortization of premiums and accretion of
      discounts on bonds held using the yield-to-maturity method. The Trust does
      not  accrue income when payment is delinquent and when management believes
      payment   is   questionable.  Realized  gains  and  losses  on  investment
      transactions  and  unrealized appreciation and depreciation of investments
      are  reported  for  financial statement and Federal income tax purposes on
      the identified cost method.

      C. USE OF ESTIMATES:
      The  preparation  of  financial  statements  in conformity with accounting
      principles  generally  accepted  in  the United States of America requires
      management  to  make  estimates  and  assumptions that affect the reported
      amounts  of assets and liabilities and disclosure of contingent assets and
      liabilities  at  the  date  of  the  financial statements and the reported
      amounts  of  revenues  and  expenses  during  the reporting period. Actual
      results could differ from those estimates.

      D. FEDERAL INCOME TAXES:
      The  Trust  has  elected  to  be taxed as a "regulated investment company"
      under   the   Internal   Revenue   Code,  and  intends  to  maintain  this
      qualification  and  to  distribute  substantially  all  of its net taxable
      income  to  its shareholders. In any year when net long-term capital gains
      are  realized  by  the  Trust, management, after evaluating the prevailing
      economic conditions, will recommend that Trustees either designate the net
      realized  long-term  gains  as  undistributed  and pay the Federal capital
      gains taxes thereon, or distribute all or a portion of such net gains.

      The  Trust  is  taxed  as  a regulated investment company and is therefore
      limited  as  to  the amount of non-qualified income that it may receive as
      the  result  of  operating  a trade or business, e.g. the Trust's pro rata
      share of income allocable to the Trust by a partnership operating company.
      The  Trust's  violation of this limitation could result in the loss of its
      status  as  a  regulated investment company, thereby subjecting all of its
      net  income  and capital gains to corporate taxes prior to distribution to
      its  shareholders.  The  Trust,  from  time-to-time, identifies investment
      opportunities in the securities of entities that could cause such trade or
      business  income  to  be allocable to the Trust. The MMPI Subsidiary Trust
      (described in Footnote 1 above) was formed in order to allow investment in
      such  securities  without  adversely  affecting  the  Trust's  status as a
      regulated investment company.

      The  MMPI Subsidiary Trust is not taxed as a regulated investment company.
      Accordingly,  prior to the Trust receiving any distributions from the MMPI
      Subsidiary  Trust,  all  of the MMPI Subsidiary Trust's taxable income and
      realized  gains,  including  non-qualified  income  and realized gains, is
      subject  to  taxation  at  prevailing  corporate tax rates. As of June 30,
      2010, the MMPI Subsidiary Trust has a deferred tax liability of $504.

      Deferred  tax  assets  and  liabilities  are recognized for the future tax
      consequences  attributable  to differences between the financial statement
      carrying  amounts  of  the  existing  assets  and  liabilities  and  their
      respective tax basis. As of June 30, 2010, the MMPI Subsidiary Trust has a
      deferred tax liability of $76,208.

      Beginning  with the 2009 annual financial statements, the Trust recognizes
      a  tax  benefit  from an uncertain position only if it is more likely than
      not that the position is sustainable, based solely on its technical merits
      and  consideration  of  the  relevant taxing authority's widely understood
      administrative  practices  and  precedents.  If this threshold is met, the
      Trust  measures  the  tax benefit as the largest amount of benefit that is
      greater  than  fifty  percent  likely  of  being  realized  upon  ultimate
      settlement.  The Trust has evaluated and determined that the tax positions
      did  not  have  a  material  effect  on the Trust's financial position and
      results of operations for the six months ended June 30, 2010.

      E. DISTRIBUTIONS TO SHAREHOLDERS:
      The Trust records distributions to shareholders from net investment income
      and  net  realized gains, if any, on the ex-dividend date. The Trust's net
      investment  income  dividend  is  declared  four times per year, in April,
      July,  October,  and  December.  The  Trust's  net  realized  capital gain
      distribution, if any, is declared in December.

      F. EXPENSE REDUCTION:
      Citibank,  N.A. ("Citibank") serves as custodian to the Trust. Pursuant to
      the  custodian  agreement,  Citibank  receives a fee reduced by credits on
      cash  balances  the Trust maintains with Citibank. All credit balances, if
      any,  used  to reduce the Trust's custodian fees are reported as fees paid
      indirectly  on  the Statement of Operations. For the six months ended June
      30, 2010, there were no credit balances used to reduce custodian fees.

3.    INVESTMENT ADVISORY AND ADMINISTRATIVE SERVICES CONTRACT
      A. SERVICES:
      Under  an  Investment  Advisory  and Administrative Services Contract (the
      "Contract")  with  the  Trust,  Babson  Capital has agreed to use its best
      efforts  to  present  to  the  Trust  a continuing and suitable investment
      program  consistent  with  the  investment  objectives and policies of the
      Trust.  Babson  Capital  represents  the  Trust  in  any negotiations with
      issuers, investment banking firms, securities brokers or dealers and other
      institutions  or  investors relating to the Trust's investments. Under the
      Contract, Babson Capital also provides administration of the
--------------------------------------------------------------------------------
                                                                              37


NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
(UNAUDITED)

      day-to-day  operations  of  the  Trust  and provides the Trust with office
      space  and  office  equipment,  accounting  and  bookkeeping services, and
      necessary   executive,   clerical   and   secretarial  personnel  for  the
      performance of the foregoing services.

      B. FEE:
      For  its  services  under the Contract, Babson Capital is paid a quarterly
      investment  advisory  fee  equal to 0.225% of the value of the Trust's net
      assets  as  of  the  last  business  day of each fiscal quarter, an amount
      approximately  equivalent  to  0.90% on an annual basis. A majority of the
      Trustees,  including  a  majority  of  the Trustees who are not interested
      persons  of  the  Trust or of Babson Capital, approve the valuation of the
      Trust's net assets as of such day.

      C. BASIS FOR BOARD RENEWAL OF CONTRACT:
      At a meeting of the Board of Trustees held on April 16, 2010, the Trustees
      (including  a majority of the Trustees who are not "interested persons" of
      the  Trust  or Babson Capital) unanimously approved a one year continuance
      of the Contract.

      Prior  to  the  meeting, the Board of Trustees requested and received from
      Ropes  & Gray LLP, counsel to the Trust, a memorandum describing the Board
      of  Trustees'  legal  responsibilities  in  connection with its review and
      reapproval  of  the  Contract.  The  Board  of Trustees also requested and
      received  from  Babson  Capital  extensive  written  and  oral information
      regarding  among  other  matters: the principal terms of the Contract; the
      reasons  why Babson Capital was proposing the continuance of the Contract;
      Babson  Capital  and  its  personnel;  the Trust's investment performance,
      including  comparative  performance information; the nature and quality of
      the  services  provided by Babson Capital to the Trust; financial strength
      of  Babson  Capital;  the  fee  arrangement between Babson Capital and the
      Trust;  fee and expense information, including comparative fee and expense
      information;  profitability of the advisory arrangement to Babson Capital;
      and "fallout" benefits to Babson Capital resulting from the Contract.

      Among  other things, the Trustees discussed and considered with management
      (i)  the  aforementioned  guidance  provided  by  Ropes & Gray LLP and the
      information provided by Babson Capital prior to the meeting, and ((ii) the
      reasons Babson Capital put forth in support of its recommendation that the
      Trustees approve the continuance of the Contract. These considerations are
      summarized below.

      NATURE, EXTENT AND QUALITY OF SERVICES TO BE PROVIDED BY BABSON CAPITAL TO
      THE TRUST

      In  evaluating  the  scope  and quality of the services provided by Babson
      Capital  to  the  Trust, the Trustees considered, among other factors: (i)
      the  scope  of  services  required to be provided by Babson Capital to the
      Trust  under  the  Contract;  (ii)  Babson  Capital's  ability to find and
      negotiate  private  placement  securities  having equity features that are
      consistent  with  the stated investment objectives of the Trust; (iii) the
      experience  and  quality  of  Babson Capital's staff; (iv) the strength of
      Babson  Capital's  financial  condition;  (v)  the  nature  of the private
      placement  market  compared  to  public  markets  (including the fact that
      finding, analyzing, negotiating and servicing private placement securities
      is  more labor-intensive than buying and selling public securities and the
      administration   of   private  placement  securities  is  more  extensive,
      expensive,  and  requires  greater  time and expertise than a portfolio of
      only  public  securities);  (vi)  the potential advantages afforded to the
      Trust  by  its  ability to co-invest in negotiated private placements with
      MassMutual  and  its  affiliates;  and (vii) the expansion of the scope of
      services  provided  by Babson Capital as a result of recent regulatory and
      legislative initiatives that have required increased legal, compliance and
      business  attention  and  diligence.  Based  on  such  considerations, the
      Trustees  concluded  that,  overall,  they  are satisfied with the nature,
      extent and quality of services provided by Babson Capital, and expected to
      be provided in the future, under the renewed Contract.

      INVESTMENT PERFORMANCE

      The  Trustees also examined the Trust's short-term, intermediate-term, and
      long-term  performance  as  compared  against  various  benchmark  indices
      presented at the meeting. In addition, the Trustees considered comparisons
      of the Trust's performance with the performance of (i) selected closed-end
      investment  companies  and  funds  that  may  invest  in private placement
      securities and/or bank loans; (ii) selected business development companies
      with  comparable  types  of  investments;  and  (iii) investment companies
      included in the Lipper closed-end bond universe. It was acknowledged that,
      while  such  comparisons  are helpful in judging performance, they are not
      directly  comparable in terms of types of investments due to the fact that
      business development companies often report returns based on market value,
      which  is affected by factors other than the performance of the underlying
      portfolio  investments.  Based  on  these  considerations and the detailed
      performance  information  provided  to  the  Trustees at the regular Board
      meetings  each  quarter,  the Trustees concluded that the Trust's absolute
      and relative performance over time have been sufficient to warrant renewal
      of the Contract.

      ADVISORY  FEE/COST  OF  SERVICES  PROVIDED  AND  PROFITABILITY/  MANAGER'S
      "FALL-OUT" BENEFITS

      In connection with the Trustees' consideration of the advisory fee paid by
      the  Trust to Babson Capital under the Contract, Babson Capital noted that
      it  was unaware of any registered closed-end investment companies that are
      directly  comparable to the Trust in terms of the types of investments and
      percentages  invested  in private placement securities (which require more
      extensive  advisory  and  administrative  services  than  a  portfolio  of
      publicly traded securities, as previously discussed) other than MassMutual
      Corporate Investors, which also is advised
--------------------------------------------------------------------------------
38

                                              MassMutual Participation Investors

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
(UNAUDITED)

      by  Babson  Capital.  Under the terms of its Investment Services Contract,
      MassMutual  Corporate Investors is charged a quarterly investment advisory
      fee  of 0.3125% of net asset value as of the end of each quarter, which is
      approximately  equal  to  1.25%  annually.  In  considering  the  fee rate
      provided  in  the Contract, the Trustees noted the advisory fee charged by
      Babson  Capital  to  Tower  Square  Capital  Partners,  L.P., Tower Square
      Capital  Partners  II,  L.P., and Tower Square Capital Partners III, L.P.,
      each  a  private  mezzanine  debt fund also managed by Babson Capital, and
      that the fee the Trust charged compares favorable.

      At  the  request  of  the  Trustees,  Babson  Capital provided information
      concerning  the  profitability  of  Babson Capital's advisory relationship
      with  the  Trust.  The  Trustees also considered the non-economic benefits
      Babson  Capital  and its affiliates derived from its relationship with the
      Trust,  including  the reputational benefits derived from having the Trust
      listed  on  the  New  York  Stock  Exchange,  and the de minimis amount of
      commissions  resulting  from  the  Trust's  portfolio transactions used by
      Babson  Capital  for  third-party  soft  dollar arrangements. The Trustees
      recognized  that  Babson  Capital  should be entitled to earn a reasonable
      level  of  profit  for  services provided to the Trust and, based on their
      review,   concluded   that  they  were  satisfied  that  Babson  Capital's
      historical level of profitability from its relationship with the Trust was
      not  excessive  and  that the advisory fee structure under the Contract is
      reasonable.

      ECONOMIES OF SCALE

      Finally,  the  Trustees  considered  the concept of economies of scale and
      possible  advisory  fee  reductions  if  the Trust were to grow in assets.
      Given  that  the  Trust  is  not continuously offering shares, such growth
      comes  principally  from  retained  net  realized  gain on investments and
      dividend  reinvestment. The Trustees also examined the breakpoint features
      of  selected  competitive  funds and noted that the minimum starting point
      for  fee  reductions in those funds was at least $200 million, whereas the
      Trust's  current  net assets are near $115 million. The Trustees concluded
      that the absence of breakpoints in the fee schedule under the Contract was
      currently  acceptable  given  the Trust's current size and closed-end fund
      structure.

4.    SENIOR SECURED INDEBTEDNESS
      MassMutual  holds  the  Trust's  $12,000,000 Senior Fixed Rate Convertible
      Note  (the  "Note")  issued by the Trust in 1995. The Note, as amended, is
      due December 13, 2011 and accrues interest at 5.80% per annum. MassMutual,
      at  its  option,  can convert the principal amount of the Note into common
      shares.  The  dollar  amount  of  principal  would  be  converted  into an
      equivalent  dollar amount of common shares based upon the average price of
      the common shares for ten business days prior to the notice of conversion.
      For  the six months ended June 30, 2010, the Trust incurred total interest
      expense on the Note of $348,000.

      The  Trust  may  redeem  the  Note,  in whole or in part, at the principal
      amount  proposed  to  be  redeemed  together  with  the accrued and unpaid
      interest  thereon  through  the redemption date plus a Make Whole Premium.
      The  Make  Whole Premium equals the excess of (i) the present value of the
      scheduled  payments  of  principal and interest which the Trust would have
      paid  but  for the proposed redemption, discounted at the rate of interest
      of  U.S. Treasury obligations whose maturity approximates that of the Note
      plus 0.50% over (ii) the principal of the Note proposed to be redeemed.

5.    PURCHASES AND SALES OF INVESTMENTS
                                                        FOR THE SIX
                                                        MONTHS ENDED
                                                         06/30/2010
                                                        ------------
                                                                     PROCEEDS
                                                 COST OF               FROM
                                                INVESTMENTS          SALES OR
                                                 ACQUIRED           MATURITIES
                                                ----------          ----------
      Corporate restricted securities           $9,108,935          $7,204,597
      Corporate public securities                6,252,863           1,610,910


      The  aggregate cost of investments is substantially the same for financial
      reporting  and  Federal  income  tax purposes as of June 30, 2010. The net
      unrealized depreciation of investments for financial reporting and Federal
      tax  purposes  as  of  June  30,  2010  is  $16,283,458  and  consists  of
      $10,655,226 appreciation and $26,938,684 depreciation.

      Net  unrealized depreciation of investments on the Statement of Assets and
      Liabilities  reflects the balance net of a deferred tax accrual of $76,208
      on net unrealized gains on the MMPI Subsidiary Trust.
--------------------------------------------------------------------------------
                                                                              39

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
(UNAUDITED)

6.    QUARTERLY RESULTS OF INVESTMENT OPERATIONS

                                                          MARCH 31, 2010
                                                     AMOUNT          PER SHARE
                                                   ----------        ----------
      Investment income                            $2,911,112
      Net investment income                         2,361,286          $0.24
      Net realized and unrealized
        gain on investments (net of taxes)            142,746           0.01

                                                          JUNE 30, 2010
                                                     AMOUNT          PER SHARE
                                                   ----------        ----------
      Investment income                            $3,007,150
      Net investment income                         2,444,394         $0.24
      Net realized and unrealized
        gain on investments (net of taxes)          3,134,736          0.32

7.    RESULTS OF SHAREHOLDER MEETING
      The Annual Meeting of Shareholders was held on Friday, April 16, 2010. The
      Shareholders  were asked to vote to re-elect as trustees Donald E. Benson,
      Donald   Glickman,   and  Robert  E.  Joyal  for  three  year  terms.  The
      Shareholders  approved  the proposals. The Trust's other Trustees, William
      J. Barrett, Michael H. Brown, Martin T. Hart, Corine T. Norgaard, Clifford
      M.  Noreen,  and  Maleyne  M. Syracuse continued to serve their respective
      terms  following  the  April  16,  2010  Annual  Shareholders Meeting. The
      results of the Shareholder voting are set forth below.

                                                                % OF SHARES
      SHARES FOR               WITHHELD          TOTAL           VOTED FOR
      ----------------------------------------------------------------------
      Donald E. Benson
      8,349,469                 262,945         8,612,414          83.59%
      Donald Glickman
      8,322,201                 290,213         8,612,414          83.31%
      Robert E. Joyal
      8,386,066                 226,348         8,612,414          83.95%


8.    BY-LAWS AMENDMENT
      On  April  16,  2010,  the  Board of Trustees approved an amendment to the
      By-Laws  of  the  Trust  to include an advance notice provision that would
      require  shareholders  seeking  to  nominate  Trustee  candidates or bring
      business  before  an annual meeting to provide timely notice to the Trust,
      consistent with certain specified requirements, of their intent to do so.

--------------------------------------------------------------------------------
40

                                              MassMutual Participation Investors


MEMBERS OF THE
BOARD OF TRUSTEES

Donald Glickman

Robert E. Joyal

William J. Barrett

Michael H. Brown*

Donald E. Benson*

Dr. Corine T. Norgaard*

Clifford M. Noreen

Martin T. Hart

Maleyne M. Syracuse

*Member of the Audit Committee



OFFICERS
Clifford M. Noreen
Chairman

Michael L. Klofas
President

James M. Roy
Vice President & Chief
Financial Officer

Patricia J. Walsh
Vice President, Secretary
& Chief Legal Officer

Jill A. Fields
Vice President

Michael P. Hermsen
Vice President

Mary Wilson Kibbe
Vice President

Richard E. Spencer, II
Vice President

Daniel J. Florence
Treasurer

John T. Davitt, Jr.
Comptroller

Melissa M. LaGrant
Chief Compliance Officer


DIVIDEND REINVESTMENT AND CASH PURCHASE PLAN

MassMutual  Participation  Investors  offers  a  Dividend  Reinvestment and Cash
Purchase  Plan  (the  "Plan").  The Plan provides a simple and automatic way for
shareholders  to  add  to  their  holdings  in  the Trust through the receipt of
dividend  shares  issued  by  the  Trust  or  through  the  reinvestment of cash
dividends  in  Trust  shares purchased in the open market. The dividends of each
shareholder  will  be  automatically  reinvested  in  the  Trust  by Shareholder
Financial Services Inc., the Transfer Agent, in accordance with the Plan, unless
such  shareholder  elects  not to participate by providing written notice to the
Transfer  Agent.  A  shareholder  may  terminate  his  or  her  participation by
notifying the Transfer Agent in writing.

Participating  shareholders  may  also make additional contributions to the Plan
from  their own funds. Such contributions may be made by personal check or other
means  in  an  amount  not less than $100 nor more than $5,000 per quarter. Cash
contributions  must be received by the Transfer Agent at least five days (but no
more then 30 days) before the payment date of a dividend or distributions.

Whenever  the  Trust declares a dividend payable in cash or shares, the Transfer
Agent,  acting  on  behalf  of  each  participating  shareholder,  will take the
dividend  in  shares  only if the net asset value is lower than the market price
plus  an  estimated  brokerage  commission  as  of  the close of business on the
valuation  day.  The valuation day is the last day preceding the day of dividend
payment.

When  the dividend is to be taken in shares, the number of shares to be received
is  determined  by  dividing  the cash dividend by the net asset value as of the
close of business on the valuation date or, if greater than net asset value, 95%
of  the closing share price. If the net asset value of the shares is higher than
the  market  value  plus an estimated commission, the Transfer Agent, consistent
with  obtaining the best price and execution, will buy shares on the open market
at current prices promptly after the dividend payment date.

The  reinvestment  of  dividends  does  not,  in  anyway,  relieve participating
shareholders  of  any  Federal,  state  or  local  tax.  For  Federal income tax
purposes,   the   amount  reportable  in  respect  of  a  dividend  received  in
newly-issued  shares  of  the  Trust will be the fair market value of the shares
received, which will be reportable as ordinary income and/or capital gains.

As compensation for its services, the Transfer Agent receives a fee of 5% of any
dividend  and cash contribution (in no event in excess of $2.50 per distribution
per shareholder.)

Any  questions  regarding  the Plan should be addressed to Shareholder Financial
Services,  Inc., Transfer Agent for MassMutual Participation Investors' Dividend
Reinvestment and Cash Purchase Plan, P.O. Box 173673, Denver, CO 80217-3673.



MASSMUTUAL
PARTICIPATION INVESTORS
























PI5075

ITEM 2.  CODE OF ETHICS.

         Not applicable for this filing.

ITEM 3.  AUDIT COMMITTEE FINANCIAL EXPERT.

         Not applicable for this filing.

ITEM 4.  PRINCIPAL ACCOUNTANT FEES AND SERVICES.

         Not applicable for this filing.

ITEM 5.  AUDIT COMMITTEE OF LISTED REGISTRANTS.

         Not applicable for this filing.

ITEM 6.  SCHEDULE OF INVESTMENTS

         A schedule of investments for the Registrant is included as part of
         this report to shareholders under Item 1 of this Form N-CSR.

ITEM 7.  DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END
         MANAGEMENT INVESTMENT COMPANIES.

         Not applicable for this filing.

ITEM 8.  PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

         Not applicable to this filing. There have been no changes in any of the
         Portfolio Managers identified in the Registrant's most recent annual
         report on Form N-CSR.

ITEM 9.  PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT
         COMPANY AND AFFILIATED PURCHASERS.

         Not applicable for this filing.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

         Not applicable for this filing.


ITEM 11. CONTROLS AND PROCEDURES.

         (a)   The principal executive officer and principal financial officer
               of the Registrant evaluated the effectiveness of the Registrant's
               disclosure controls and procedures (as defined in Rule 30a-3(c)
               under the Investment Company Act of 1940 (the "Act")) as of a
               date within 90 days of the filing date of this report and based
               on that evaluation have concluded that such disclosure controls
               and procedures are effective to provide reasonable assurance that
               material information required to be disclosed by the Registrant
               on Form N-CSR is recorded, processed, summarized and reported
               within the time periods specified in the Securities and Exchange
               Commission's rules and forms.

         (b)   There were no changes in the Registrant's internal control over
               financial reporting (as defined in Rule 30a-3(d) under the Act)
               during the Registrant's second fiscal quarter that have
               materially affected, or are reasonably likely to materially
               affect, the Registrant's internal control over financial
               reporting.

ITEM 12. EXHIBITS.

        (a)(1) ANY CODE OF ETHICS, OR AMENDMENTS THERETO, THAT IS THE SUBJECT OF
               DISCLOSURE REQUIRED BY ITEM 2, TO THE EXTENT THAT THE REGISTRANT
               INTENDS TO SATISFY THE ITEM 2 REQUIREMENTS THROUGH THE FILING OF
               AN EXHIBIT.

               None.

        (a)(2) A SEPARATE CERTIFICATION FOR EACH PRINCIPAL EXECUTIVE OFFICER AND
               PRINCIPAL FINANCIAL OFFICER OF THE REGISTRANT AS REQUIRED BY RULE
               30a-2 UNDER THE ACT.

               Attached hereto as EX-99.31.1
               Attached hereto as EX-99.31.2

        (a)(3) ANY WRITTEN SOLICITATION TO PURCHASE SECURITIES UNDER RULE 23c-1
               UNDER THE ACT (17 CFR 270.23c-1) SENT OR GIVEN DURING THE PERIOD
               COVERED BY THE REPORT BY OR ON BEHALF OF THE REGISTRANT TO 10 OR
               MORE PERSONS.

               Not applicable for this filing.

        (b)    CERTIFICATIONS PURSUANT TO RULE 302-2(b) UNDER THE ACT.

               Attached hereto as EX-99.32


                                   SIGNATURES

            Pursuant to the requirements of the Securities Exchange Act of 1934
and the Investment Company Act of 1940, the Registrant has duly caused this
report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant):   MassMutual Participation Investors
                ----------------------------------
By:             /s/ Michael L. Klofas
                ----------------------------------
                Michael L. Klofas, President
                ----------------------------------
Date:           September 8, 2010
                ----------------------------------

            Pursuant to the requirements of the Securities Exchange Act of 1934
and the Investment Company Act of 1940, this report has been signed below by the
following persons on behalf of the Registrant and in the capacities and on the
dates indicated.

By:             /s/ Michael L. Klofas
                ----------------------------------
                Michael L. Klofas, President
                ----------------------------------
Date:           September 8, 2010
                ----------------------------------
By:             /s/ James M. Roy
                ----------------------------------
                James M. Roy, Vice President and
                Chief Financial Officer
                ----------------------------------
Date:           September 8, 2010
                ----------------------------------