Osisko Canadian Malartic Mine Produces Half Millionth Ounce

MONTRÉAL, QUÉBEC--(Marketwire - Oct. 11, 2012) - Osisko Mining Corporation (the "Company" or "Osisko") (TSX:OSK)(FRANKFURT:EWX) is very proud to announce that on Tuesday, October 9th, the Company produced its 500,000^th ounce from its flagship Canadian Malartic Mine.

Seven years ago, in March 2005, Osisko commenced initial exploration drilling at Canadian Malartic. Over the course of the following four and a half years, the Company completed over 800,000 metres of definition drilling, feasibility studies and permitting. Construction of the Canadian Malartic Mine started in August 2009 and was completed in just 19 months, and dore bar 001 was proudly poured at site on April 13^th, 2011. Since that date, nearly 1000 gold-silver dore bars have been poured in the first 18 months of ramp-up operations. As of January 1, 2012, reserves at Canadian Malartic stood at 10.7 million ounces of gold.

The Company would like to congratulate the operations management and all of the over 600 employees at Canadian Malartic for the outstanding work they have done to bring this world-class deposit to this milestone in such a short period of time, and would like to thank them for their continued commitment to striving to make Canadian Malartic Quebec's largest gold producer.

Mr. Robert Wares, P. Geo., Executive Vice President, Exploration and Resource Development for Osisko, is the Qualified Person who has reviewed this news release and is responsible for the technical information reported herein, including verification of the data disclosed.

About Osisko Mining Corporation

Osisko Mining Corporation operates the Canadian Malartic Gold Mine in Malartic, Quebec and is pursuing exploration on a number of properties, including the Hammond Reef Gold Project in Northern Ontario.