Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F. 

Form 20-F ___X___ Form 40-F _______

Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes _______ No___X____

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Commercial Viability Announcement in the BM-S-7 Block

(Rio de Janeiro, April 6, 2009). – PETRÓLEO BRASILEIRO S/A - PETROBRAS, [Bovespa: PETR3/PETR4, NYSE: PBR/PBRA, Latibex: XPBR/XPBRA, BCBA: APBR/APBRA], a Brazilian international energy company, announces that the Consortium of Petrobras (63%-Operator) and Repsol (37%) has delivered a Declaration of Commercial Viability to the National Petroleum Agency (ANP) with respect to a light oil and gas discovery in reservoirs above the salt layer in the BM-S-7 Block in the Santos Basin. This discovery had been announced after the drilling of the well 6-BRSA-661-SPS (6-SPS-53) in January 2009. The new field, known as Piracucá, is located off the coast of the state of São Paulo, approximately 200 km from the city of Santos in a water depth of 200 meters. The total volume of the reserve in situ is estimated at 88.5 million m3 (about 550 million barrels of oil equivalent).

The Declaration of Commercial Viability was made pursuant to the Concession Contract for the BM-S-7 Block according to the established term in the Evaluation Plan submitted to the ANP and represents the result of the Consortium’s intense exploratory activity in this block.

Additional analysis will be required to decide upon the best method for developing production in the field.

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www.petrobras.com.br/ri/english
Contacts: PETRÓLEO BRASILEIRO S. A. – PETROBRAS
Investor Relations Department I E-mail: petroinvest@petrobras.com.br / acionistas@petrobras.com.br
Av. República do Chile, 65 – 22^nd floor - 20031-912 - Rio de Janeiro, RJ I Tel.: 55 (21) 3224-1510 / 9947

This document may contain forecasts that merely reflect the expectations of the Company’s management. Such terms as “anticipate”, “believe”, “expect”, “forecast”, “intend”, “plan”, “project”, “seek”, “should”, along with similar or analogous expressions, are used to identify such forecasts. These predictions evidently involve risks and uncertainties, whether foreseen or not by the Company. Therefore, the future results of operations may differ from current expectations, and readers must not base their expectations exclusively on the information presented herein.

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This press release may contain forward-looking statements. These statements are statements that are not historical facts, and are based on management's current view and estimates offuture economic circumstances, industry conditions, company performance and financial results. The words "anticipates", "believes", "estimates", "expects", "plans" and similar expressions, as they relate to the company, are intended to identify forward-looking statements. Statements regarding the declaration or payment of dividends, the implementation of principal operating and financing strategies and capital expenditure plans, the direction of future operations and the factors or trends affecting financial condition, liquidity or results of operations are examples of forward-looking statements. Such statements reflect the current views of management and are subject to a number of risks and uncertainties. There is no guarantee that the expected events, trends or results will actually occur. The statements are based on many assumptions and factors, including general economic and market conditions, industry conditions, and operating factors. Any changes in such assumptions or factors could cause actual results to differ materially from current expectations.

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