6 August 2010

Participation in the Block 117, the Maranon Basin, Onshore Peru

INPEX CORPORATION (INPEX) is pleased to announce that its wholly owned subsidiary
INPEX North Peru, Ltd. (INPEX Peru) has been granted approval by the Peruvian authority
and that it has executed all the related contracts to acquire a 25% participating interest of
the Block 117 with Petrobras Energía Perú S.A. (PESA), through. This is the first time for
INPEX to participate in an oil and gas exploration activity in Peru, while INPEX has been
involved in a number of exploration, development and production activities in Latin
American countries, such as Venezuela, Brazil, Ecuador, Mexico and Suriname.

The Block 117 is located in the Maranon Basin, the northern part of Peru, which covers an
area of 10,940km2. In this Block, PESA will continue to operate with a 50% participating
interest, while Colombian national oil company Ecopetrol and INPEX Peru each hold a 25%
participating interest. INPEX Peru will carry out exploring for hydrocarbons resources in
the Block. Several large reserves of oil have been discovered and produced in the vicinity
of the Block 117.

INPEX will further endeavor to expand upstream exploration and production in Latin
American countries, which are INPEX’s one of international core business areas.

Media Contact: INPEX Tokyo Office, Public Relations Group, Tel) +81-3-5572-0233