2010-03-16-2010-01-06-2010-01-06

Entered JV to acquire 50% WI in 7,250 acres in Haynesville shale in LA & TX, 19,750 acres in Marcellus play in west PA.

Houston-based Endeavour International Corp. (NYSE Amex: END; London: ENDV) has acquired interests in the Haynesville shale play in North Louisiana and East Texas and the Marcellus shale play in western Pennsylvania from Cohort Energy Co., a subsidiary of J-W Operating Co., for undisclosed drilling carries.

This transaction is in addition to the acquisition of producing assets from Cohort in North Louisiana and East Texas previously announced on Oct. 30, 2009, for $15 million.

Total assets include a 50% working interest in approximately 66,000 gross acres (27,000 net). Cohort will be operator.

In the Haynesville play, the deal involves 17,700 gross acres (7,250 net) with about 50% held by production. Upside includes more than 200 potential drilling locations with potential in the Hosston, Cotton Valley and Bossier formations.

The Marcellus assets involve 48,300 gross acres (19,750 net) with about 44%held by production in Cameron, McKean, Potter, Elk, Jefferson and Clarion counties, Pennsylvania. Upside includes more than 300 potential drilling locations.

William L. Transier, Endeavour chairman, chief executive officer and president says, "This transaction represents the second part of a broad joint venture Endeavour has established with Cohort and J-W Operating Co. Cohort has a track record of success as an operator in the Barnett shale play that will serve us well in the exploitation of these highly prospective positions in the Haynesville and Marcellus shale plays."

Endeavour could participate in drilling more than 500 horizontal wells over the next 10 to 15 years in these two plays.

Miller Mentzer PC was legal advisor to Cohort. Burleson Cooke LLP was legal advisor to Endeavour.