Penn West Energy enters Arrangement Agreement to acquire Vault Energy Trust for approx $380 mln; expected to be accretive

Co announces that it has entered into an Arrangement Agreement to acquire all of the outstanding units, exchangeable shares and warrants of Vault Energy Trust. The acquisition will be accomplished through a Plan of Arrangement wherein each Vault trust unit will be exchanged for 0.14 of a Penn West trust unit and all Vault exchangeable shares will be exchanged for Penn West trust units based on the exchange ratio for Vault units in effect at the effective date of the Arrangement. The transaction exchange ratio represents a premium to Vault Unitholders of 6% based on the respective volume weighted average unit trading price for each trust for the ten trading days up to September 24, 2007. Including the assumption of Vault's total debt including its convertible debentures, the total acquisition cost is expected to be approximately $380 mln. It is expected that approximately 5.5 mln Penn West trust units will be issued to effect the Arrangement. The acquisition is expected to be accretive to Penn West's unitholders on a production, cash flow and reserves basis.