ARC Acknowledges Financial Exposure to SemGroup, L.P. Filing under Chapter 11

CALGARY, July 22 /CNW/ - ARC Resources Ltd. ("ARC") a subsidiary of ARC
Energy Trust ("The Trust") has a potential exposure of $26.2 million from oil
sales for the months of June and July 2008 to SemGroup, L.P.'s subsidiary,
SemCanada Crude Company for the marketing of a portion of ARC's oil
production. SemGroup, L.P., a mid-stream and marketing company filed a
voluntary petition for reorganization under Chapter 11 of the Bankruptcy Code
in the United States Bankruptcy Court for the District of Delaware. SemGroup
listed assets of $6.14 billion and liabilities of $7.53 billion in its
bankruptcy filing. As of this date ARC is not certain of what portion if any
of the $26.2 million is collectible but in any case the amount is not
considered material to ARC's operations and overall financial position.

ARC Energy Trust is one of Canada's largest conventional oil and gas
royalty trusts with an enterprise value of approximately $7.5 billion. The
Trust expects full year 2008 oil and gas production to average approximately
64,000 barrels of oil equivalent per day from six core areas in western
Canada. ARC Energy Trust units trade on the TSX under the symbol AET.UN and
ARC Resources exchangeable shares trade under the symbol ARX.

Note: Barrels of oil equivalent (boe) may be misleading, particularly if
used in isolation. In accordance with NI 51-101, a boe conversion ratio for
natural gas of 6 mcf:1 bbl has been used, which is based on an energy
equivalency conversion method primarily applicable at the burner tip and does
not represent a value equivalency at the wellhead.

ADVISORY - In the interests of providing ARC unitholders and potential
investors with information regarding ARC, including management's assessment of
ARC's future plans and operations, certain information contained in this
document are forward-looking statements within the meaning of the "safe
harbour" provisions of the United States Private Securities Litigation Reform
Act of 1995 and the Ontario Securities Commission. Forward-looking statements
in this document include quantification of exposures and liabilities to
July 22, 2008 resulting from the marketing of ARC's oil production to
SemCanada Crude Company which is based on certain information and assumptions
including certain bankruptcy filings of SubGroup L.P. and their effect on and
information from SemCanada Crude Company. Readers are cautioned not to place
undue reliance on forward-looking statements, as there can be no assurance
that quantification of exposures and liabilities or expectations upon which
they are based will occur. By their nature, forward-looking statements involve
numerous assumptions, known and unknown risks and uncertainties, both general
and specific, that contribute to the possibility that the predictions,
forecasts, projections and other forward-looking statements will not occur,
which may cause ARC's actual performance and financial results in future
periods to differ materially from the quantification of exposures and
liabilities or projections of future performance or results expressed or
implied by such forward-looking statements.

ARC RESOURCES LTD.

John P. Dielwart,
President and Chief Executive Officer