UPDATE 2-First Quantum disappointed by Inmet's rejection of bid

(Adds further detail, updates shares)

Nov 29 (Reuters) - First Quantum Minerals Ltd said on Thursday it believed Inmet Mining Corp's board was selling shareholders short by refusing to enter into talks on a takeover proposal put forward by First Quantum earlier this month.

Toronto-based Inmet, which is building the huge Cobre Panama copper mine in Central America, said on Wednesday it had turned down a C$4.86 billion ($4.89 billion) unsolicited proposal from its larger rival, saying the offer was "highly conditional" and not in the best interests of its shareholders.

"First Quantum is both surprised and disappointed at the circumstances under which the Inmet board chose to forego this significant opportunity," First Quantum Chief Executive Philip Pascall said in a statement.

Vancouver, British Columbia-based First Quantum, which owns assets in Africa, Australia, South America and Europe, said it believes that Inmet shareholders would support a transaction that offers immediate and attractive cash value for the shares.

First Quantum said it had approached Inmet on three separate occasions during the last two months to engage in discussions, but Inmet has spurned all its overtures.

Under First Quantum's proposal, the company is offering up to C$2.461 billion in cash and would issue a maximum of 112.679 million shares, in a deal that values Inmet at C$70 a share, or C$4.86 billion. This follows an initial bid of C$62.50 that was put forward by First Quantum in October.

Shares of Inmet, which closed at C$52.80 on Tuesday, rose more than 17 percent to C$62 following news of the First Quantum offer on Wednesday. Inmet shares rose a further 4.2 percent on Thursday to C$64.65.

First Quantum shares were down slightly less than a percent at C$20.64 in midday trading on the Toronto Stock Exchange.

($1 = 0.9936 Canadian dollars)

(Reporting by Euan Rocha; Editing by Gerald E. McCormick and Tim Dobbyn)