HOUSTON, January 21 /PRNewswire/ —
Endeavour International Corporation (Amex: END) (LSE: ENDV) today
announced a successful up-dip appraisal of the Rochelle undeveloped discovery
in Block 15/27 of the UK North Sea. Endeavour holds a 55.6 percent interest
in the well and is operator for the block. Nexen Petroleum U.K. Limited is a
joint venture participant and holds 44.4 percent interest.

The Rochelle 15/27-11 appraisal well was drilled to a total depth of
10,369 feet subsea encountering 77 feet net pay in the Lower Cretaceous
Kopervik sandstone with average porosity of 24 percent and average
hydrocarbon saturation of 86 percent. Pressure data and samples confirm 55
feet of gas on top of 22 feet of oil. The oil water contact was not
encountered. Plans are in progress to flow test the well. The reservoir
characteristics measured in 15/27-11 are much better than predicted in our
pre-drill estimates. Endeavour’s preliminary post-drill best technical case
could be in excess of 30 million barrels of oil equivalent gross recoverable.

The company intends to move quickly towards development of Rochelle.
Future appraisal/development options are being actively evaluated.

“Rochelle is the first successful appraisal project planned, executed,
and operated by Endeavour. Rather than farm down working interest to
interested parties, Endeavour elected to retain its majority interest based
on extensive in-house technical and commercial work. The Rochelle appraisal
is an excellent example of maturing a fallow discovery toward development as
envisaged by the regulatory authorities when they began seeking new entrants,
like Endeavour, into the United Kingdom sector earlier this decade. We will
use the results of this well to plan the next phase in the development of
Rochelle. This is a significant success for Endeavour on its own and it will
breathe new life into our R Blocks area comprised of 15/27 and 15/28b,” said
William L. Transier, Chairman and Chief Executive Officer.

The 15/27-11 appraisal well was drilled approximately two kilometers
northwest of the 15/27-9 discovery well drilled in 2000. Endeavour acquired
Rochelle in 2006. It is in the Outer Moray Firth in the prolific Kopervik
sand fairway between the Goldeneye and Brodgar producing fields.

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 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.

Endeavour International Corporation

Investor Relations, Mike Kirksey of Endeavour International Corporation, +1-713-307-8788; or Jeffrey Auld of Canaccord Adams, +44-(0)-207-050-6500; or UK Media, Philip Dennis, +44-(0)-207-743-6363, or Henry Lerwill, +44-(0)203-178-6242, both of Pelham Public Relations, all for Endeavour International Corporation