PRESS RELEASE Malabo – March 16th, 2011   SIGNATURE OF NEW PRODUCTION SHARING CONTRACT, BLOCK D, OFFSHORE BIOKO The Ministry of Mines, Industry and Energy is pleased to announce that a new Production Sharing Contract (PSC) for Block D, Offshore Bioko, was signed in Houston, Texas, USA on February 26th, 2011. The Block D PSC is between the Republic of Equatorial Guinea, represented by the Ministry of Mines, Industry and Energy, and the contractor group consisting of GEPetrol, the National Oil Company of Equatorial Guinea, Marathon E.G. Production Limited and SK Innovation Co., Ltd.   Marathon E.G. Production Limited, a wholly-owned subsidiary of Marathon Oil Corporation, serves as operator of Block D with a participating interest of 70.6 percent.  GEPetrol holds a 20 percent participating interest with SK Innovation Co., Ltd holding the remaining 9.4 percent interest.