PETRÓLEO BRASILEIRO S.A. - PETROBRAS

MATERIAL FACT

Petrobras’ Proven Reserves in 2012

Rio de Janeiro, January 14^th, 2013 – Petróleo Brasileiro S.A. –  Petrobras announces its proved oil and natural gas reserves, assessed at the end of 2012 according to the Securities and Exchange Commission – SEC criteria.

Petrobras’ Proven Reserves in 2012

On December 31^st, 2012 proven reserves according to SEC criteria reached 12.884 billion boe, representing an increase of 0.1% from the previous year, distributed as shown:

In 2012, 0.896 billion boe were appropriated to Proven Reserves and 884 million boe were produced, resulting in an increase of 0.011 billion boe compared to 2011 reserves (12.873 billion boe).

According to SEC criteria, for each barrel of oil equivalent extracted in 2012, 1.01 barrels of oil equivalent were appropriated, resulting in a reserve replacement ratio of 101%. The Reserves-to-Production Ratio (R/P) was 14.6 years.

Proven Reserves in Brazil

On December 31^st, 2012 proved oil and natural gas reserves in fields under Petrobras’ concession in Brazil, according to SEC criteria, reached 12.263  billion barrels of oil equivalent (boe), representing the maintenance of 2011 proven reserves.

In 2012, 0.822 billion boe were appropriated to Proven Reserves, compared to a cumulative production of 0.815 billion boe, as shown below:

For each barrel of oil equivalent extracted in 2012, 1.01 barrels of oil equivalent were appropriated, resulting in a Reserve Replacement Ratio of 100.9%. The Reserves-to-Production (R/P) ratio was 15 years.

The main Proven Reserves incorporations in 2012 were:

•    ongoing success of exploratory activities in the post-salt in different Brazilian basins:

- incorporation of volumes related to new discoveries close to the existing infrastructure of the Golfinho field, in Espírito Santo Basin; Marlim Sul field, in Campos Basin; and Araçás, Cexis, Fazenda Panelas and Taquipe fields, in Recôncavo Basin;

- declaration of commerciality in the following fields: Tartaruga Verde and Tartaruga Mestiça in Campos Basin; Baúna and Piracaba in Santos Basin; and Piranema Sul and Arapaçu in Sergipe-Alagoas Basin.

•    rise in proven reserves in the pre-salt due to an increase in well drilling activities and positive responses from production systems in operation both in the Campos and Santos Basins. Most of it came from the Lula/Cernambi and Sapinhoá concessions, where Petrobras is the operator and registers volumes proportional to its stake in these concessions: 65% and 45%, respectively.

International Proven Reserves

On December 31^st, 2012 Petrobras’ proved oil and natural gas reserves abroad, according to SEC criteria, were 0.621 billion boe, an increase of 0.6% from the previous year.

In 2012, 0.074 billion boe were appropriated to Proven Reserves, compared to a cumulative production of 0.069 billion boe, as shown below:

According to SEC criteria, for each barrel of oil equivalent extracted in 2012, 1.07 barrels of oil equivalent were appropriated, resulting in a reserve replacement ratio of 107%. The Reserves-to-Production Ratio (R/P) was 9 years.

In 2012, main Proven Reserves incorporations were:

•    Revaluation of the Chinook field in deep waters of the Gulf of Mexico;

•    Review of the Agbami Development Plan in deep waters of Nigeria;

•    Inclusion of volumes associated to the secondary recovery at Akpo field in deep waters of Nigeria.

Petrobras clarifies that the hydrocarbon reserve properties belong to their respective National States.