UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
Under the Securities Exchange Act of 1934
(Amendment No. __1___ )*
NetScout Systems Inc.
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(Name of Issuer)
Common Stock, $.001 par value per share
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(Title of Class of Securities)
64115T104
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(CUSIP Number)
December 31, 2005
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(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:
[ X ] Rule 13d-1(b)
[ ] Rule 13d-1(c)
[ ] Rule 13d-1(d)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities,
and for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.
The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).
SCHEDULE 13G
CUSIP No. 64115T104
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1. Names of Reporting Persons. I.R.S. Identification Nos. of above
persons (entities only).
AMVESCAP PLC Atlantic Trust Company, N.A.
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2. Check the Appropriate Box if a Member of a Group (see
Instructions)
(a)
(b)
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3. SEC Use Only _______________________________________________
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4. Citizenship or Place of Organization
AMVESCAP PLC: England
Atlantic Trust Company, N.A.: United States
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5. Sole Voting Power 11,657,382: Such
shares are held by the following
entities in the respective amounts
listed: Atlantic Trust Company, N.A.
11,657,382
Number of Shares ----------------------------------------------------
Beneficially Owned
by Each Reporting 6. Shared Voting Power _________
Person With
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7. Sole Dispositive Power 11,657,382: Such
shares are held by the following
entities in the respective amounts
listed: Atlantic Trust Company, N.A.
11,657,382
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8. Shared Dispositive Power ______
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9. Aggregate Amount Beneficially Owned by Each Reporting Person
11,657,382
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10. Check if the Aggregate Amount in Row (9) Excludes Certain Shares
(See Instructions) N/A
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11. Percent of Class Represented by Amount in Row (9) 37.52%
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12. Type of Reporting Person (See Instructions)
IA, HC. See Items 2 and 3 of this statement.
SCHEDULE 13G
Item 1(a) Name of Issuer:
NetScout Systems, Inc.
Item 1(b) Address of Issuer's Principal Executive Offices:
310 Littleton Road
Westford, MA 01886
Item 2(a) Name of Person Filing:
AMVESCAP PLC
In accordance with Securities and Exchange Commission Release
No. 34-39538 (January 12, 1998), this statement on Schedule
13G or amendment thereto is being filed by AMVESCAP PLC
("AMVESCAP"), a U.K. entity, on behalf of itself and its
subsidiaries listed in Item 4 of the cover of this statement.
AMVESCAP through such subsidiaries provides investment
management services to institutional and individual investors
worldwide.
Executive officers and directors of AMVESCAP or its
subsidiaries may beneficially own shares of the securities of
the issuer to which this statement relates (the "Shares"),
and such Shares are not reported in this statement. AMVESCAP
and its subsidiaries disclaim beneficial ownership of Shares
beneficially owned by any of their executive officers and
directors. Each of AMVESCAP's direct and indirect
subsidiaries also disclaim beneficial ownership of Shares
beneficially owned by AMVESCAP and any other subsidiary.
Item 2(b) Address of Principal Business Office:
11 Devonshire Square
London EC2M 4YR
England
Item 2(c) Citizenship:
See the response to Item 2(a) of this statement.
Item 2(d) Title of Class of Securities:
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Common Stock, $.001 par value per share
Item 2(e) CUSIP Number:
64115T104
Item 3 Type of Reporting Person:
An investment adviser in accordance with section
240.13d-1(b)(1)(ii)(E) A parent holding company or control
person in accordance with section 240.13d-1(b)(1)(ii)(G)
As noted in Item 2 above, AMVESCAP is making this filing on
behalf of its subsidiaries listed herein. Each of these
entities is either an investment adviser registered with the
United States Securities Exchange Commission under Section
203 of the Investment Advisers Act of 1940, as amended, or
under similar laws of other jurisdictions. AMVESCAP is a
holding company.
Item 4 Ownership:
Please see responses to Items 5-8 on the cover of this
statement which are incorporated herein by reference.
Item 5 Ownership of Five Percent or Less of a Class:
N/A
Item 6 Ownership of More than Five Percent on Behalf of Another
Person:
N/A
Item 7 Identification and Classification of the Subsidiary Which
Acquired the Security Being Reporting on By the Parent
Holding Company: Please see Item 3 of this statement, which
is incorporated herein by reference.
Item 8 Identification and Classification of Members of the Group:
N/A
Item 9 Notice of Dissolution of a Group:
N/A
Item 10 Certification:
By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired
and are held in the ordinary course of business and were not
acquired and are not held for the purpose of or with the
effect of changing or influencing the control of the issuer
of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having
that purpose or effect.
Signature:
After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.
February 13, 2006
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Date
/s/ Lisa Brinkley
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Signature
Lisa Brinkley
Chief Compliance Officer
AMVESCAP PLC