The Caisse de dépôt et placement du Québec sells common shares of Atlantic
Power Corporation

MONTREAL , Dec. 8 /CNW Telbec/ - The Caisse de dépôt et placement du Québec (the "Caisse") announces that it has sold, to a group of investors, 11,497,000 common shares of Atlantic Power Corporation (TSX: APT) ("Atlantic Power" or the "Company"), or 18.99% of such shares outstanding at a price of $10.60 per share.

Before this transaction, Caisse held $36,501,000 of subordinated notes that it had acquired on November 18, 2004 , and 11,497,000 common shares or 18.99% of such shares outstanding. Pursuant to this transaction, Caisse no longer holds common shares of the Company.

This transaction was made for investment purposes and the Caisse could increase or decrease its investments in the Company, depending on market conditions or any other relevant factor.

For further information: Maxime Chagnon, Caisse de dépôt et placement du Québec, [phone]