Osisko responds to below market price offer for five million shares only by TRC Capital

MONTREAL, QUEBEC–(Marketwire – Jan. 3, 2012) – Osisko Mining Corporation (TSX:OSK)(FRANKFURT:EWX) ("Osisko" or the "Company") has been notified of an unsolicited "mini-tender" offer, made by TRC Capital Corporation ("TRC Capital") on December 23, 2011, to purchase up to 5,000,000, or approximately 1.297% of Osisko's common shares, at a price of CDN $9.55 per share. Osisko does not recommend or endorse this unsolicited offer.

Shareholders are cautioned that the offer has been made at a 4.12% discount to the closing price for Osisko's shares on the Toronto Stock Exchange on December 22, 2011, being the day before the offer was announced.

Shareholders should also be advised that TRC Capital has reserved the right to withdraw its offer at any time, at its sole discretion and also reserved the right to decline to purchase all deposited shares if all conditions are not satisfied, including in the event that the offer price exceeds the market price of Osisko's shares at the applicable time.

The Company does not endorse TRC Capital's unsolicited mini-tender offer and is not associated with TRC Capital, the mini-tender offer or the offer documentation. TRC Capital has made many similar unsolicited mini-tender offers for shares of other companies. Mini-tender offers are designed to seek less than 5% of a company's outstanding shares, thereby avoiding many disclosure and procedural requirements applicable to most bids under Canadian securities legislation.

Shareholders are cautioned that they should consult their investment advisors and exercise extreme caution regarding the TRC Capital offer.

The Canadian Securities Administrators ("CSA") have expressed serious concerns about mini-tender offers such as the possibility that investors might tender to a mini-tender offer based upon a misunderstanding of the terms of the offer, including the per security price available under the offer relative to the market price of such securities. Comments from the CSA on mini-tenders can be found on the Ontario Securities Commission website at: http://www.osc.gov.on.ca/en/SecuritiesLaw_csa_19991210_61-301.jsp. The U.S. Securities and Exchange Commission has published investor tips regarding mini-tender offers on its website at: http://www.sec.gov/investor/pubs/minitend.htm.

According to TRC Capital's current offer documents, Osisko shareholders who have already tendered their shares may withdraw their shares at any time before 5:00 p.m. (Toronto time) on January 24, 2012, by following the procedures described in the offer documents.

About Osisko

Osisko Mining Corporation, based in Montreal, Quebec, 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.