ARC Resources Ltd./ARC Energy Trust Announce the September 2007 increase to the ARX Exchangeable Shares Exchange Ratio

Sep 4, 2007

CALGARY, Sept. 4 /CNW/ - (AET.UN and ARX - TSX) ARC Resources Ltd. along
with ARC Energy Trust announces the increase to the exchange ratio of the
exchangeable shares of the corporation from 2.16283 to 2.18448. Such increase
will be effective on September 17, 2007.
The following are the details on the calculation of the exchange ratio:

<<
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Record date Opening ARC 10 day Increase Effective Exchange
of ARC exchange Energy weighted in date of ratio
Energy Trust ratio Trust average exchange the as of
distribution distri- trading ratio increase effective
bution price of (xx) in date
per AET.UN exchange
unit (prior to ratio
the end
of the
month)
-------------------------------------------------------------------------
August 31, 2.16283 $0.20 $19.9767 0.02165 September 2.18448
2007 17, 2007
-------------------------------------------------------------------------

(xx) The increase in the exchange ratio is calculated by dividing the ARC
Energy Trust distribution per unit by the 10 day weighted average
trading price of AET.UN and multiplying by the opening exchange
ratio.
>>

A holder of ARC Resources Ltd. exchangeable shares can exchange all or a
portion of their holdings at any time by giving notice to their investment
advisor or Computershare Investor Services at its principal transfer office in
Suite 600, 530 - 8th Avenue SW, Calgary, Alberta, T2P 3S8, their telephone
number is 1-800-564-6253 and their website is www.computershare.com.

ARC RESOURCES LTD.
John P. Dielwart,
President and Chief Executive Officer

For further information: about ARC Energy Trust, please visit our website www.arcenergytrust.com or contact: Investor Relations, E-mail: ir@arcresources.com, Telephone: (403) 503-8600, Fax: (403) 509-6417, Toll Free 1-888-272-4900, ARC Resources Ltd., 2100, 440 - 2nd Avenue S.W., Calgary, AB, T2P 5E9