Exhibit 15.1

KPMG Auditores Independentes	Central Tel	55 (21) 3515-9400
Av. Almirante Barroso, 52 — 4º	Fax	55 (21) 3515-9000
20031-000 — Rio de Janeiro, RJ — Brasil	Internet	www.kpmg.com.br
Caixa Postal 2888
20001-970 — Rio de Janeiro, RJ — Brasil

To
Petróleo Brasileiro S.A.—Petrobras
Rio de Janeiro, RJ — Brazil

December 11, 2009

     We acknowledge our awareness of the incorporation by reference in the Registration Statement on Form F-3 of Petróleo Brasileiro S.A.—Petrobras (“Petrobras”), of our report dated November 27, 2009, relating to the unaudited consolidated interim financial statements of Petrobras for the nine months ended September 30, 2009, included in its Form 6-K furnished to the SEC on November 27, 2009.

     Pursuant to Rule 436 under the Securities Act of 1933 (the “Act”), such report is not considered part of a registration statement prepared or certified by an independent registered public accounting firm, or a report prepared or certified by an independent registered public accounting firm within the meaning of Sections 7 and 11 of the Act.

/s/ KPMG Auditores Independentes KPMG Auditores Independentes

Rio de Janeiro, RJ — Brazil