UPDATE 1-Osisko sets deal with Yamana to foil hostile Goldcorp bid

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TORONTO, April 2 (Reuters) - Osisko Mining Corp said on Wednesday that Yamana Gold Inc would buy a 50 percent stake in its mining and exploration assets for C$930 million ($843 million), in a deal aimed at blocking a hostile bid from rival Goldcorp.

Yamana will pay C$441.5 million in cash and the rest in common stock, and the company will be an equal partner in all of Osisko's mining and exploration assets.

The deal calls for the exchange of each Osisko share for C$2.194 in cash, 0.2119 of a Yamana common share and a new common share of Osisko. Based on Tuesday's closing prices, that would value Osisko at C$7.60 per share.

The stock was up 8.9 percent at C$7.49 in morning trading. Shares of Goldcorp rose 2.6 percent to C$27.78, while Yamana gained 1.4 percent to C$9.84.

Vancouver-based Goldcorp on Jan. 13 launched a C$2.6 billion cash and stock bid for Osisko to gain control of its Malartic gold mine in the province of Quebec.

The bid was first attempt at an acquisition by a Canadian gold company in nearly a year. Deals had dried up after several of Goldcorp's peers wrote down billions of dollars of assets bought at sky-high prices as the bullion price ran up.

Osisko rejected Goldcorp's unsolicited bid as too low and has been building a case that its shareholders stand to benefit most if it remains a standalone company.

Osisko said on Wednesday that it would still operate its flagship Canadian Malartic Mine and all other projects under the guidance of a joint committee. It will also maintain its head office in Montreal.

Osisko's board has unanimously approved the deal with Yamana, and the company said it would hold a special meeting next month for shareholders to vote on the transaction. ($1 = 1.1029 Canadian dollars)

(Reporting by Euan Rocha; Editing by Bernadette Baum and Lisa Von Ahn)