Joint Venture On Windfall Gold Project

TORONTO - Osisko Mining Inc. has concluded a 50/50 joint venture agreement with a subsidiary of Gold Fields Limited for the joint ownership and development of Osisko's Windfall gold project, located in the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Quebec.

Osisko's Chairman and Chief Executive Officer, John Burzynski, said, “We are very pleased to partner with Gold Fields on the Windfall project and our exploration property portfolio. Today is the start of what we believe will prove to be a long and fruitful partnership with Gold Fields at Windfall, and in what we both believe is a significant emerging gold district in Quebec. This partnership further strengthens our strong balance sheet, allows us to significantly de-risk Windfall and brings us a very important step closer to realizing our objective of becoming a leading Canadian gold producer. With the proceeds from this Transaction, Osisko is fully-funded for our share of development capital to bring Windfall into production. Osisko shareholders retain considerable upside in the project while also benefiting from the mine building, operating and technical expertise of Gold Fields. Assuming the project is ultimately permitted and approved by the partners consistent with the Windfall Feasibility Study, Gold Fields’ acquisition cost, exploration commitment, and contribution to pre-construction and project capital would ultimately represent an investment of C$1.2 billion to acquire its interest, bring Windfall into production and further unlock the regional exploration upside. This Transaction is highly compelling on many fronts and represents the best path forward to maximize value for all stakeholders.

Osisko Mining would like to acknowledge and thank Sean Roosen in particular and the directors of Osisko Gold Royalties Ltd. (“OGR”) for their forward-looking vision in supporting the 2015 re-creation of Osisko Mining - one of the key first investment decisions in OGR’s very innovative and successful “accelerator model” concept to create new high-value negative-cost royalties tied to equity investment in new exploration companies. OGR holds a 2% - 3% NSR royalty on the Windfall area claims and 13% of the undiluted equity in the Corporation.”