Lundin Mining Corp. formally launched its hostile takeover of Nevsun Resources Ltd. Thursday after it said successive proposals to buy the Vancouver-based miner were rejected by its board.

Paul Conibear, Lundin’s chief executive officer, urged Nevsun shareholders to support the takeover, arguing the company will need significant financing to develop its Timok copper-gold project in Serbia and the Bisha mine in Eritrea. There is a risk they won’t be developed properly without it, he said.

He argued Lundin is better positioned to provide that financing and develop the projects. Lundin has been trying to reach an agreement to acquire Nevsun since October.

“Each of five successive proposals made since early February were rejected by Nevsun despite multiple moves by us to address their concerns on structure, bidding partner and price,” Conibear said on a conference call. “Each time we presented a proposal, the goal post changed.”

He said his firm is better able to provide financing to develop the project over the next four or five years than Nevsun could on its own. He pointed to the development of its nickel-copper Eagle Mine in Michigan and its Candelaria mining complex in Chile as examples of its successful track record.

‘Not Limited’

Conibear said Lundin was not limited by financial capacity to invest in new assets and optimize them. He said Lundin would ramp up exploration on Timok once it got its feet on the ground and fast track the development of its upper zone.

Lundin would take a “wait and see” approach to Bisha, he said. He said the mine has had a great history and that he knew there is a lot of untapped geological potential in the region because one of the Lundin group companies used to own two of the deposits that are not yet in the mill.

“We think we could add a great deal of value there,” he said.

Conibear warned that Nevsun’s shares would likely plunge if the deal is rejected.

A representative for Nevsun wasn’t immediately available for comment.

Lundin commenced its tender offer to acquire Nevsun Thursday. Under the terms of the offer, Nevsun shareholders would receive C$4.75 in cash for each Nevsun share tendered, representing an 82 per cent premium to the closing price prior to Feb. 6, the date it first proposed taking over the company. Nevsun holders have until Nov. 9 to tender their shares.

Nevsun shares closed Wednesday in Toronto at $4.76 apiece, giving the miner a market value of $1.4 billion.

The Toronto-based miner announced Wednesday Marie Inkster, its current chief financial officer, will take over as CEO by the end of the year, replacing Conibear, 61, who will retire.

"I’m grateful and excited for the opportunity to lead our team and continue building on the excellent track record of Lundin Mining," she said on the call. "As many of you know, Paul and I have been working closely together for many years to grow Lundin Mining and keep the company strong through the cycles."

Inkster has almost 20 years experience in the industry, including a decade with Lundin. Prior to joining the company in 2008, she held various senior positions, including as a vice-president at LionOre Mining International Ltd.