(New throughout, adds details and background, updates share price)
VANCOUVER, May 8 (Reuters) - Shares in Nevsun Resources leaped on Tuesday even as it said its board of directors had unanimously rejected an unsolicited C$1.5 billion ($1.16 billion) takeover proposal from Lundin Mining Corp and Euro Sun Mining as too low with a "problematic structure".
Copper-zinc miner Nevsun said in a statement the offer was rejected after several months of engagement with fellow Canadian base metals miner Lundin on a possible deal.
Even so, Nevsun's shares surged 17 percent to C$4.46 on the Toronto Stock Exchange. That was still below the C$5 a share the takeover proposal values the company at. Lundin's shares fell 3.5 percent to C$7.94 and Euro Sun's were down 1.4 percent at C$1.35.
Lundin and Euro Sun disclosed on Monday that they had made an offer on April 30 to buy Vancouver-based Nevsun. The offer included C$2 in cash funded by Lundin, C$2 in shares of Lundin and C$1 in shares of Euro Sun.
They said they had made public their offer as they believed Nevsun's shareholders should be "made aware of this opportunity".
Nevsun said the proposal undervalues its Timok copper-gold project in Serbia. It also said that Euro Sun, a small non-operating mining company, was "not an attractive partner" and has had difficulty raising financing.
$1 = 1.2967 Canadian dollars Reporting by Nicole Mordant in Vancouver Editing by Chizu Nomiyama and David Gregorio