MOECO acquired interests of Block 104-109/05 offshore northern Vietnam

February 28, 2008 Project

Mitsui Oil Exploration Co., Ltd. ("MOECO", Head office: Hibiya Central Bldg. 2-9, Nishi Shimbashi 1-Chome, Minato-ku, Tokyo, Japan/ President: Mr. Yoshiyuki Kagawa) is pleased to announce that Moeco (Song Hong) Co., Ltd.("MSH"), wholly-owned subsidiary of MOECO, entered into Production Sharing Contract with Vietnam Oil and Gas Group and Premier Oil Vietnam North B.V., a subsidiary of Premier Oil plc. to acquire 50% interests of Block 104-109/05 offshore northern Vietnam on February 27, 2008.

The offshore block is located in unexplored area in the gulf of Tonkin, northern Vietnam. MOECO decided to acquire the block based upon its geological hopefulness. Premier is the operator of the block and hold a 50% interests. Japan Oil, Gas and Metals National Corporation ("JOGMEC") will provide MSH with financial support.

MOECO is currently active in Thailand, Cambodia, Indonesia, Middle East, the United States, Libya and Vietnam.

MOECO's acquisition of an interest in the offshore block provides an excellent opportunity to further expand its business in Vietnam, and contributes to Vietnamese economic growth and making a new job opportunities for Vietnamese people, and a successful discovery in the block would create its strategic core for future expansion.