EXHIBIT 99.1


                       AMERICAN NATURAL ENERGY CORPORATION
                           6100 South Yale, Suite 300
                              Tulsa, Oklahoma 74136
                       Tel: 918-481-1440 Fax: 918-481-1473


      AMERICAN NATURAL ENERGY CORPORATION ANNOUNCES PARTICIPATION AGREEMENT

TULSA, OKLAHOMA, SEPTEMBER 14, 2005. American Natural Energy Corporation
("ANEC") (TSX Venture: ANR.U) announced that it has entered into a
participation agreement ("Agreement") with Dune Energy, Inc. ("Dune") (AMEX:
DNE).  Pursuant to the Agreement, which was subject to ExxonMobil Production
Company consent finalized on September 12, 2005, Dune will acquire certain
exploration and development rights in ANEC's ExxonMobil Joint Development
Agreement covering the Bayou Couba field in St. Charles Parish, Louisiana.

The Agreement provides Dune with the right to participate in 50% of ANEC's
development rights in the Bayou Couba lease in exchange for the payment of $1
million. Dune may also participate in the exploration rights in the ExxonMobil
acreage in exchange for the payment of an additional $500,000. Each party will
pay their respective share of drilling, completion and operations costs. The
Agreement is subject to completion of a final definitive agreement.

Additionally, ANEC announced the completion of the drilling of the DSCI 92ST
well in the Bayou Couba field. The well, drilled to a vertical depth of
approximately 6,040 feet, is producing approximately 300 barrels of oil and 280
mcf of natural gas per day from a 12/64" choke. ANEC has a 15.625% working
interest in the well. ANEC has commenced operations on the DSCI 51ST in which it
will have a 20.625% working interest. The well is expected to be drilled to
approximately 7,500 feet. ANEC's working interests reflect the interests earned
by Dune pursuant to the Agreement.

ANEC also announced that damage from the recent Katrina hurricane was minimal
and that production from the field, after being down for approximately 10 days,
has resumed.

ANEC is a Tulsa, Oklahoma based independent exploration and production company
with operations in St. Charles Parish, Louisiana. For further information please
contact Michael Paulk, CEO at 918-481-1440 or Steven P. Ensz, CFO at
281-367-5588.

The TSX Venture Exchange has not reviewed and does not accept responsibility for
the adequacy or accuracy of this release.


This Press Release may contain statements which constitute forward-looking
statements within the meaning of the US Private Securities Litigation Reform Act
of 1995, including statements regarding the plans, intentions, beliefs and
current expectations of ANEC, its directors, or its officers with respect to the
future business, well drilling and operating activities and performance of ANEC.
Investors are cautioned that any such forward-looking statements are not
guarantees of future performance and involve risks and uncertainties. The actual
results and outcome of events may differ materially from those in the
forward-looking statements as a result of various factors. The levels of and
fluctuations in the prices for natural gas and oil and the demand for those
commodities, the outcome of ANEC's development and exploration activities,
including the success of its current and proposed well drilling


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activities and the availability of capital to pursue those activities could
affect ANEC and its future prospects. ANEC's inability to raise additional
capital would adversely affect its ability to pursue its drilling program and
its liquidity. Important additional factors that could cause such differences
are described in ANEC's periodic reports and other filings made with the
Securities and Exchange Commission and may be viewed at the Commission's Website
at http://www.sec.gov.


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