Agreement to acquire 55.3% interest in a Peruvian gold mining company

September 6, 2004--Cambior is pleased to announce that it has entered into an agreement with a group of private shareholders ("Selling Group") to acquire a 55.3% interest in the private Peruvian mining company Compania Minera Poderosa S.A. ("CMPSA") and the Selling Group's advances to CMPSA totaling $8 million. CMPSA owns and operates the Poderosa mine located in the Pataz Province of Northern Peru. The mine has produced 1.25 million ounces of gold since 1982, with an average of 75,000 ounces produced annually over the last five years. Targeted gold production for 2004 is estimated at 109,000 ounces at a total cash cost of $175 per ounce.

Cambior will pay the Selling Group, at closing, a cash amount of $25 million and will issue approximately 2.2 million common shares of Cambior for the Selling Group's interest and advances, and may, at some future date, pay additional consideration of up to $6 million subject to the outcome of certain contingent liabilities. As of June 30, 2004, CMPSA had outstanding bank and creditors' debts of $34.7 million, including $18.2 million in shareholders' advances (including the aforementioned $8 million advances from the Selling Group). The transaction is expected to close within the next 60 days, and closing is subject to a number of conditions, including Cambior obtaining financing to fund the transaction. Cambior has entered into discussions with several financial institutions to fund this acquisition.

CMPSA produces high grade ore from a series of underground mines which utilize both mechanized and conventional mining methods. Total ore treatment capacity is 800 tonnes per day and includes cyanide leaching and Merrill Crowe processing. In 2003, the mine produced 90,500 ounces of gold at total cash cost of $209 per ounce.

 Cambior's Strategy in Peru

Louis P. Gignac, President and CEO of Cambior, commented on the acquisition as follows: "We are pleased to acquire the control position of an established operation in Peru in an area with tremendous potential for future development. This acquisition will allow Cambior to establish a third base of mining operations to complement its operations located in Canada and the Guiana Shield. The Poderosa high grade mine will provide immediate growth and additional gold exposure to Cambior. Cambior has been active in Peru since 1993, and is currently pursuing the delineation of various deposits in the Huamachuco area."

Peru is the world's sixth largest gold producing country and is host to a number of world-class base metal and precious metal deposits with great geological potential.

Development Plan

Cambior looks forward to working with its Peruvian partners to enhance the financial performance of CMPSA, and investing in further exploration and development to delineate additional mineral resources and reserves and expand production over time.