HOUSTON, February 10 /PRNewswire/ --

Endeavour International Corporation (Amex: END) (LSE: ENDV) today announced that the Cygnus 44/12a-3 appraisal well in the Southern Gas Basin in the North Sea has successfully extended the productive area of the Cygnus field by confirming the presence of recoverable gas reserves in a second fault block. Endeavour holds a 12.5 percent interest in the Cygnus field area spread over two United Kingdom blocks, 44/11a and 12a. License partners include GDF SUEZ, the operator, and Venture Production Plc.

The well was drilled to a total depth of 12,433 feet and flow tested at rates up to 32 million cubic feet of gas per day. The parameters of the secondary Carboniferous reservoir interval substantially exceed pre-drill expectations and gross reserves are estimated to be in excess of 100 billion cubic feet. A further appraisal well will be drilled immediately in a third fault block approximately eight kilometers northwest of the 44/12a-3 following completion of the well.

A field development plan for Cygnus was submitted to the United Kingdom governing authority, Department of Energy and Climate Change, in December 2008 and contained a phased development scenario that called for initial production to begin in the fourth quarter of 2010.

Stated William L. Transier, chairman and chief executive officer of Endeavour:

The excellent result of this appraisal well confirms what Endeavour and its joint venture partners believe is one of the largest gas discoveries in the UK sector of the Southern Gas Basin in the last decade. This positive news in the Cygnus area comes on the heels of the successful appraisal of our Rochelle discovery in Block 15/27. Our company now has three significant gas development projects underway that should more than double our current production in the 2010 and 2011 timeframe. We are now beginning to see evidence that the potential of our undeveloped discoveries will surpass our best expectations. Endeavour is maturing into a well capitalized, self-funded and balanced exploration and development company.

Endeavour International Corporation is an oil and gas exploration and production company focused on the acquisition, exploration and development of energy reserves in the North Sea and the United States. For more information, visit http://www.endeavourcorp.com

Certain statements in this news release should be regarded as forward-looking statements within the meaning of the securities laws. These statements speak only as of the date made. Such statements are subject to assumptions, risk and uncertainty. Actual results or events may vary materially.

Investor Relations, Mike Kirksey of Endeavour, +44(0)207-451-2360, or +1-713-307-8788; UK Broker, Jeffrey Auld of Cannacord Adams, + 44(0)207-050-650; or Public Relations - UK Media, Philip Dennos, +44(0)207-743-6363, or Henry Lerwill, +44(0)203-178-6242, both of Pelham Public Relations, for Endeavour