MONTREAL, QUEBEC--(Marketwired - May 30, 2014) - Osisko Mining Corporation (TSX:OSK)(FRANKFURT:EWX) ("Osisko") is in receipt of motion materials from Abitibi Royalties Inc. ("Abitibi") seeking to, among other things, enforce contractual rights under a joint venture agreement in relation to 10 claims known as the Malartic CHL Prospect (the "CHL Prospect") in which Abitibi holds a 30% interest and Osisko holds the remaining 70% interest, prior to completion of the plan of arrangement ("Arrangement") between Osisko, Agnico Eagle Mines Limited ("Agnico Eagle") and Yamana Gold Inc. ("Yamana"). Osisko will defend the claims vigorously and believes the claims are opportunistic and entirely without merit.

The CHL Prospect is located north-east of, and proximate, but not immediately adjacent to, the Canadian Malartic Mine. The CHL Prospect is undeveloped and includes the Jeffrey Zone, which comprises a portion of Osisko's current reserve estimate but is not considered material by Osisko. No mining permits are currently held on the CHL Prospect. There are no known resources or reserves on eight of the ten claims of the CHL Prospect.

Mr. Robert Wares, D.Sc., P. Geo., Senior 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

Osisko Mining Corporation operates the Canadian Malartic Gold Mine in Malartic, Québec and is pursuing exploration on a number of properties, notably in Québec, Ontario and Mexico.

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 Osisko 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, the results of litigation between Osisko and Abitibi and the satisfaction of all technical, economical, regulatory and financial conditions in order to complete the Arrangement between Osisko, Agnico Eagle and Yamana, the realization of all expected benefits of this Arrangement. Although Osisko believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, 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, results of litigation, timeliness of government or court approvals,. These factors are discussed in greater detail in Osisko's most recent Annual Information Form, which is filed on SEDAR and also provide additional general assumptions in connection with these statements. Osisko cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on the forward looking statements contained herein should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. Osisko 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. Osisko undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, other than as required by applicable law.