TORONTO, Feb 10 (Reuters) - Canadian base metal miner HudBay Minerals Inc said it plans to buy exploration company Augusta Resource Corp in a bid to gain control of its Rosemont project in Arizona, an asset widely viewed as one of the most promising copper projects in the United States.
The strategically timed bid, announced late Sunday, comes just weeks before Augusta is expected to receive final approvals that would allow it to begin development and construction work on the asset that could account for as much as 10 percent of U.S. copper output, making Rosemont the third largest copper mine in the country.
Rosemont, located some 50 kilometers (31 miles) southeast of Tucson, is expected to begin operations in 2016 and produce 243 million pounds of copper, along with about 2.9 million ounces of silver and 5.4 million pounds of molybdenum, annually.
The $1.2 billion project is set to become the No. 3 copper mine in the United States, behind Freeport-McMoRan Copper & Gold Inc's Morenci mine in Arizona and Rio Tinto's Bingham Canyon Mine in Utah.
"We view the Rosemont project as an attractive complement to our existing portfolio of high quality, long-life assets," said HudBay's Chief Executive David Garofalo in a statement.
The unsolicited all-stock proposal from Toronto-based HudBay offers Augusta's shareholders a premium of 18 percent over the company's closing price of C$2.51 on the Toronto Stock Exchange on Friday.
Augusta shares surged 25 percent to C$3.14 in early trading on Monday, well above the value of HudBay's bid, indicating that investors expect a sweetened bid to emerge. HudBay's shares fell 5.5 percent to C$8.88 on the TSX.
Analysts expect rival bids to emerge, as they argue HudBay's current offer does not reflect the strategic value and advanced permitting status of the project.
"Given the scale of Rosemont and favorable geopolitical risk profile, we see the potential for other bidders to emerge," said National Bank analyst Steve Parsons, in a note to clients.
Based on Friday's closing price, HudBay is offering to pay C$2.96 per share for all the shares in Augusta it does not own.
Augusta shareholders will be entitled to receive 0.315 of one HudBay common share for each Augusta common share held, valuing the company at about C$455 million ($413 million). HudBay said the enterprise value of the deal could be about C$540 million.
HudBay currently owns about 23.1 million shares in Augusta, representing about 16 percent of the company's outstanding shares. HudBay made its initial investment in Augusta in 2010.
Vancouver-based Augusta said late on Sunday that its board will meet this week to discuss the HudBay offer and it urged its shareholders not to take any action until the company decides on the next course of action.
Jennings Capital analyst Peter Campbell said he believes the offer "significantly undervalues Augusta" and he views the bid as being "very opportunistic."
"We believe that shareholders who have been in Augusta for the long-term, and have held on throughout the lengthy stage of permitting the project, would be giving up significant value by accepting this offer," he wrote in a note to clients.
Augusta has already secured some of the financing to fund the construction of the Rosemont project. In 2010, the company signed an earn-in agreement with a South Korean consortium that is comprised of Korea Resources Corp and LG International Corp .
The agreement allows the Korean consortium to acquire a 20 percent interest in the project in return for a $176 million investment. Augusta is also using $230 million that it received from a separate deal with Silver Wheaton Corp to fund the project.
HudBay said its offer will be open until March 19, unless extended or withdrawn. The offer is subject to all customary conditions, receipt of the necessary regulatory approvals and no material adverse change in Augusta's status.
Analysts believe the material adverse change clause allows HudBay to hedge its bets, giving it an exit option in the event of an unfavorable ruling on Augusta's permits.
HudBay has retained BMO Capital Markets and GMP Securities as its financial advisers, with Goodmans LLP and Milbank, Tweed, Hadley & McCloy LLP acting as legal counsel.