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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Another oil-bearing well discovered in the Santos Basin’s Pre-Salt layer

(Rio de Janeiro, December 20, 2007). – 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 formed by Petrobras (80% - Operator) and Galp Energia (20%) to explore block BM-S-21, in deep Santos Basin waters, via well 1-BRSA-526-SPS (1-SPS-51), has proven there is a light oil field in the pre-salt layer in the Santos Basin. The pioneer well is located 280 km off the coast of the State of São Paulo (view the figure below), 2,234 meters below sea surface. The well’s depth is 5,350 m.

The discovery, communicated to the NPA pursuant to the legislation in effect, was proved through signs of oil and via profile interpretation, in reservoirs nestled at a depth of nearly 5,000 meters. The well has not been tested yet due to operating and logistics reasons.

The Consortium will undertake the necessary activities and make the required investments to check the field’s dimensions and verify the oil reservoir’s characteristics. Furthermore, it is elaborating the Discovery Evaluation Plan it will send to the NPA, as provided for in the Concession Agreement.

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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