(Montreal, October 07, 2011) During a ceremony held yesterday, Sean Roosen, President and CEO of Osisko Mining Corporation (“Osisko”), was named Ernst & Young’s 2011 Quebec Entrepreneur of the Year. Furthermore, he is among the five individuals to be nominated for the national honor of Canada’s 2011 Entrepreneur of the Year, being announced in Toronto on November 23.

The Quebec Entrepreneur of the Year Award is given annually to an entrepreneur who has distinguished himself by his achievements, not only in terms of business success, but also in terms of socio-economic development within the community.

“I am extremely proud to receive one of Canada’s most prestigious awards”, noted Sean Roosen. “I humbly accept this award on behalf of the entire Osisko team—now counting over 700 employees—who are the ones truly responsible for the success of the Company.”

“I especially want to share this recognition with four colleagues in particular: fellow co-founders of Osisko, Robert Wares and John Burzynski, as well as Bryan Coates, Chief Financial Officer, and Luc Lessard, Chief Operating Officer, who joined the Company early on in its development. These four Quebec entrepreneurs merit the honor bestowed by Ernst & Young. Osisko was a shared vision, and together we have designed, planned and brought it to fruition.”

Osisko: creating stakeholder value

The award given to Sean Roosen and his colleagues serves to recognize the quality achievements attained by the Company in a notably accelerated period of time.

Osisko’s success began with the discovery of a gold deposit in Malartic, Quebec—a site that saw production between 1935 to 1983, and which was thought to have been exhausted. By applying an innovative model of analysis, Osisko’s geologist, Robert Wares, uncovered the deposit’s tremendous potential, which was then gradually confirmed by an exploration program, approximately worth $100 million.

Unlike the majority of junior exploration companies, who generally sell their discoveries to large producer mining companies, Osisko’s business plan was to take an exploration project into production and to create a new mining company. The Canadian Malartic mine began commercial production in May 2011.

The Quebec Entrepreneur of the Year award acknowledges not only the quality of this achievement, but also recognizes the challenges faced while leading the project to completion, including:

•Realizing the existence of a world class deposit at a site that was thought to be exhausted.
•Earning the trust, respect and cooperation of Malartic’s local community—as the deposit is located on the border of the mining town of Malartic, home to approximately 3800 inhabitants.
•Negotiating jointly with the local municipality as well as with the residents, in the planning of the relocation of a neighborhood—in order to make way for the mine site.
•Recruiting a qualified and complete team needed for the development, construction and mining of the deposit.
•Raising the funds necessary for the development and construction of one of the most significant Canadian gold mines—$1.2 billion, during a time when the financial market was in crisis, turmoil and uncertainty.
A company worth no more than $5.5 million in the market in 2003, Osisko now possesses a market value of approximately $ 5.4 billion, making it one of the ten largest companies in Quebec.

A model citizen

Corporate citizenship is a focal criterion in determining the recipient of the Ernst & Young Entrepreneur award. Osisko has taken numerous actions in this respect:

•Selecting a production process which will restore one of the most polluted and abandoned mine waste sites in Quebec. In doing so, it is estimated that the Quebec government will save $8.5 million.
•Using the relocation of a neighborhood of Malartic as an opportunity to improve the quality of its urban infrastructure and amenities.
•Creating the Fund Essor Malartic Osisko (“FEMO”), a sustainable development fund for the citizens of Malartic, worth $4.5 million even prior to the start-up of the mine.
•Establishing a procurement policy that ensures the hiring and support of local vendors, suppliers, and workers, as well as training programs aimed at developing the talent and know-how of local and regional workforces. From 2008 to 2010, Osisko invested $760 million into the Quebec economy, including $500 million in Abitibi-Témiscamingue.
“Beyond our commercial success, we are especially proud of our contribution made to the development of Abitibi-Témiscamingue and Quebec”, explains Sean Roosen. “It is our goal to pursue our development and to further increase this contribution. We hope that our Company’s success will inspire and encourage other Quebec-based mining companies to do the same.”

About Osisko

Founded in 1998, Osisko is headquartered in Montreal, Quebec. Devoted primarily to mineral exploration at the onset, the Company later transitioned into a producer, with the development of the Canadian Malartic Mine. Osisko continues exploration activities within Quebec in the Abitibi area, Canada and elsewhere in the world.

Osisko employs more than 700 individuals.

Forward Looking Statements

Certain statements contained in this press release may be deemed “forward-looking statements”. All statements in this release, other than statements of historical fact, that address events or developments that the Corporation expects to occur, are forward looking statements. Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words “expects”, “plans”, “anticipates”, “believes”, “intends”, “estimates”, “projects”, “potential”, “scheduled” and similar expressions, or that events or conditions “will”, “would”, “may”, “could” or “should” occur including, without limitation, increasing of throughput at the mill to achieve design capacity, improving mill feed grade, maintaining recovery rates and increasing gold production. Although the Corporation believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, including, without limitation that the diligent ongoing optimizing of its operations will be achieved and will, accordingly, improve its operating performance, such statements are not guarantees of future performance and actual results may differ materially from those in forward looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include gold prices, the Corporation’s limited experience with production and development stage mining operations, uninsured risks, regulatory changes or sanctions, defects in titles, availability of personnel, materials and equipment, timeliness of government approvals, actual performance of facilities, equipment and processes relative to specifications and expectations, unanticipated environmental impacts on operations market prices, continued availability of capital and financing and general economic, market or business conditions. These factors are discussed in greater detail in the Corporation’s most recent Annual Information Form filed on SEDAR, which also provides additional general assumptions in connection with these statements. The Corporation cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on the Corporation’s forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. The Corporation believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct and such forward-looking statements included in this press release should not be unduly relied upon. These statements speak only as of the date of this press release.