The fire incident of a drilling rig in the Gulf of Mexico

May 10, 2010 Project

Mitsui Oil Exploration Co., Ltd. (''MOECO'') announced today that on April 20, 2010, a third party semi-submersible drilling rig, which was conducting exploration work on the Mississippi Canyon 252 block in the Gulf of Mexico, experienced a fire incident, which sank the drilling rig and resulted in leakage of hydrocarbons from the well, as reported in the press. MOEX Offshore 2007 LLC, a 100% subsidiary of MOEX USA Corporation (a 100% subsidiary of MOECO), has a 10% working interest in the block as a non-operator, which is operated by BP Exploration and Production Inc. A full response is being conducted by the operator, the drilling rig owner and government entities. MOECO maintains insurance policies.

MOECO is unable, at this time, to determine the cause of the incident, and the impact, if any, that the incident will have on MOECO's future operating results, financial position or cash flows.