(In penultimate paragraph, corrects market cap rankings)
* C$5.95/shr cash-and-stock offer represents 15 pct premium
* Goldcorp says bid to remain open until Feb. 19
* Osisko shares up 19 percent; Goldcorp shares slip
By Euan Rocha
TORONTO, Jan 13 (Reuters) - Goldcorp Inc launched an unsolicited cash-and-stock bid to acquire smaller rival Osisko Mining Corp for C$2.6 billion ($2.4 billion) on Monday, in a move to gain control of Osisko's Malartic gold mine in Quebec.
The takeover bid is the Canadian gold sector's first major attempt at a merger and acquisition deal in nearly a year. Miners stung by a 25 percent drop in the price of gold over the last 12 months have focused on cutting costs and slowing down work on growth projects.
The acquisition of the large low-grade Malartic deposit will boost Goldcorp's proven and probable reserves by some 10 million ounces, but it also carries its own set of perils.
"Given the low grade of the reserves, the Osisko assets will be relatively susceptible to any further weakness in the gold price, though the Canadian dollar will help protect the domestic mining industry," wrote JPMorgan analyst John Bridges in a note to clients.
The Canadian dollar hit a four-year low against the U.S. dollar last week, after data showed the country unexpectedly shed jobs last month. A weak Canadian dollar typically helps miners with assets within Canada, as most of their costs are denominated in Canadian dollars, while gold sales are in U.S. dollars.
Vancouver-based Goldcorp's bid, which works out to C$5.95 per share, represents a 15 percent premium to Osisko's closing share price on Friday.
Goldcorp said Osisko shareholders would receive 0.146 of a Goldcorp share plus C$2.26 in cash for each share they own. The bid will be open until Feb. 19.
Shares in Osisko rose 19 percent in early trading on the Toronto Stock Exchange to C$6.18, indicating that investors are expecting Goldcorp to sweeten its offer.
"Our clear preference remains to engage with Osisko, as we strongly believe in the compelling strategic and financial merits of this transaction to the mutual benefit of both companies' shareholders," said Goldcorp's Chief Executive Chuck Jeannes in a statement.
A spokeswoman for Osisko was not immediately reachable for comment.
With most major gold miners from Barrick Gold Corp to Newmont Mining Corp struggling with a major setbacks on key growth projects, analysts doubt that Osisko will be able to find a white knight to counter the Goldcorp bid.
"Given the depressed Osisko share price and Goldcorp's track record of identifying value, some owners may hold out for a better bid, but given Goldcorp's industry dominance we don't expect to see a superior bid," said Bridges.
Goldcorp said its offer will not require the approval of its own shareholders. The miner has obtained a $1.25 billion credit facility from Scotiabank which, together with cash on hand, and an undrawn $2 billion credit facility, will be sufficient to fund the cash portion of the offer.
Malartic, Osisko's only operating mine, is likely to produce 500,000 to 600,000 ounces of gold per year over its 16-year mine life, according to the company's website. The mine located in the prolific Abitibi mining district began commercial production in May 2011.
Osisko also owns the Hammond Reef and the Kirkland Lake gold projects in Northern Ontario.
"Overall, we believe that both the producing mine as well as the potential development assets fit well within the geographical risk profile of Goldcorp's current portfolio of mines, which are located across North and South America," wrote Barclays analyst Farooq Hamed in a note to clients.
Goldcorp has said it expects to produce between 3.0 million and 3.15 million ounces of gold this year, an increase of 13 to 18 percent from 2013.
Goldcorp was until recently the world's largest gold company by market capitalization, but it was surpassed again by Barrick Gold, after the world's biggest gold producer issued $3 billion in equity late last year.
Goldcorp's shares, which closed at C$25.29 on Friday on the Toronto Stock Exchange, fell 3.6 percent to C$24.38 in early trading on Monday. Its New York-listed shares fell 3.5 percent after the morning bell on Monday. ($1 = 1.09 Canadian dollars) (Reporting by Euan Rocha in Toronto and Swetha Gopinath in Bangalore; Editing by Saumyadeb Chakrabarty, Sriraj Kalluvila and Chizu Nomiyama)