Osisko Comments on Trading of Common Shares

MONTREAL, QUEBEC--(Marketwire - Dec. 14, 2011) - Osisko Mining Corporation (TSX:OSK)(FRANKFURT:EWX) ("Osisko" or the "Company") states that it is not aware of any information or change in the affairs of the Company that would account for the current market fluctuations in the price of the common shares of the Company.

Ramp-up at the Canadian Malartic mine, including construction of the pre-crush unit, is on schedule as per the forecast announced in the November 14, 2011 press release.

About Osisko

Osisko Mining Corporation, based in Montreal, Que., is a company focused on acquiring, exploring, developing and mining gold properties, with the aim of becoming a mid-tier gold producer. Its flagship project is the Canadian Malartic gold mine in the Abitibi mining district, which represents the single biggest gold reserve in production in Canada with proven and probable reserves of 10.7 million ounces of gold. Osisko is included on the S&P/TSX Composite Index, the leading indicator of market performance based on Canada's major corporations.