Endeavour Announces Closing of Convertible Notes Offering and Full Exercise of Over-Allotment Option

HOUSTON, July 22, 2011 -

Endeavour International Corporation (NYSE: END) (LSE: ENDV)
today announced the closing of its previously-announced private
placement of $135 million aggregate principal amount of 5.5%
convertible senior notes due 2016 (the “2016 Notes”), which
includes the full exercise by the initial purchasers of their
option to purchase an additional $15 million principal amount of
the 2016 Notes.  Endeavour intends to use substantially all of
the net proceeds of this offering to fund its pending acquisition
of acreage and related midstream assets in the Marcellus shale
play.  The remainder will be used for general corporate
purposes.

This press release is neither an offer to sell nor the
solicitation of an offer to buy the 2016 Notes or any other
securities.  The 2016 Notes were offered to qualified
institutional buyers in reliance on Rule 144A under the Securities
Act of 1933 (the “Securities Act”).  The 2016 Notes have not
been registered under the Securities Act and may not be offered or
sold in the United States without registration or an applicable
exemption from registration requirements.  This announcement
is being issued pursuant to Rule 135c under the Securities Act and
shall not constitute an offer to sell or the solicitation of an
offer to buy any securities.

This press release contains
forward-looking statements within the meaning of Section 27A of the
Securities Act of 1933 and Section 21E of the Securities Exchange
Act of 1934. These forward-looking statements include statements
that express a belief, expectation, or intention, as well as those
that are not statements of historical fact, and may include
projections and estimates concerning the timing and success of
specific projects and our future production, revenues, income and
capital spending.  Our forward-looking statements are
generally accompanied by words such as “estimate,” “project,”
“predict,” “believe,” “expect,” “anticipate,” “potential,” “plan,”
“goal” or other words that convey the uncertainty of future events
or outcomes.  We caution you not to rely on them unduly.
 We have based these forward-looking statements on our current
expectations and assumptions about future events.  While our
management considers these expectations and assumptions to be
reasonable, they are inherently subject to significant business,
economic, competitive, regulatory and other risks, contingencies
and uncertainties, most of which are difficult to predict and many
of which are beyond our control.  These risks, contingencies
and uncertainties, which may not be exhaustive, relate to, among
other matters, the following: discovery, estimation, development
and replacement of oil and gas reserves; decreases in proved
reserves due to technical or economic factors; drilling of wells
and other planned exploitation activities; timing and amount of
future production of oil and gas; the volatility of oil and gas
prices; availability and terms of capital; operating costs such as
lease operating expenses, administrative costs and other expenses;
our future operating or financial results; amount, nature and
timing of capital expenditures, including future development costs;
cash flow and anticipated liquidity; availability of drilling and
production equipment; uncertainties related to drilling and
production operations in a new region; cost and access to natural
gas gathering, treatment and pipeline facilities; business strategy
and the availability of acquisition opportunities; and factors not
known to us at this time.  Any of these factors, or any
combination of these factors, could materially affect our future
financial condition or results of operations and the ultimate
accuracy of a forward-looking statement.  The forward-looking
statements are not guarantees of our future performance, and our
actual results and future developments may differ materially from
those projected in the forward-looking statements.  In
addition, any or all of our forward-looking statements included in
this release may turn out to be incorrect.  They can be
affected by inaccurate assumptions we might make or by known or
unknown risks and uncertainties, including those included in our
Annual Report on Form 10-K for the year ended December 31, 2010.
 There can be no assurance that we will complete the Marcellus
acquisition.  

Endeavour International Corporation is an international 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
href="www.endeavourcorp.com/">www.endeavourcorp.com.

Mike Kirksey, +1-713-307-8700, or Darcey Matthews, +1-713-807-8711, both of Endeavour - Investor Relations