Osisko Mining Corp.

Global Inferred resource increases to 10.52 million ounces gold

MONTREAL, QUEBEC -- (Marketwire) -- 11/07/11 -- Osisko Mining Corporation (TSX: OSK)(FRANKFURT: EWX) is pleased to provide an updated inferred resource estimate for its 100%-owned Hammond Reef gold project, located near Atikokan, Ontario. New drilling by Osisko and Brett Resources from January 2010 to July 2011 (approximately 300,000 metres) has significantly increased the size of the deposit. This update reports both global and in-pit resources in the inferred category. Additional drilling subsequent to July 2011 is anticipated to allow for the upgrade of the entire in-pit deposit to Measured and Indicated category by Q1 2012.

Osisko provides early update on Q3 operating results and ramp up at Canadian Malartic

MONTREAL, QUEBEC -- (Marketwire) -- 10/19/11 -- Osisko Mining Corporation ('Osisko' or the 'Company') (TSX: OSK)(FRANKFURT: EWX) was advised by Investment Industry Regulatory Organization of Canada on behalf of the Toronto stock exchange that its stock was halted based on recent trading activity. Osisko is not aware of any corporate developments to account for this activity.

A first in the Quebec mining industry

MONTREAL, QUEBEC -- (Marketwire) -- 10/17/11 -- Osisko Mining Corporation ('Osisko' or the 'Company') (TSX: OSK)(FRANKFURT: EWX) is proud to announce it has deposited the amount of $22.1 million with the Quebec Government, representing 50 % of the financial guarantee of $44.2 million, to cover the entire future cost of rehabilitating its new Canadian Malartic mine site in the Abitibi region of Quebec. The balance of the guarantee will be remitted as two subsequent payments of $11.05 million each, to be made on or around September 1, 2012 and September 1, 2013.

MONTREAL, ONTARIO -- (Marketwire) -- 10/07/11 -- Editors' note: A photo is associated with this press release.

During a ceremony held yesterday, Sean Roosen, President and CEO of Osisko Mining Corporation ('Osisko')(TSX: OSK)(FRANKFURT: EWX), 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