Silver miner Fresnillo said over the week-end that its joint venture, Minera Penmont, is throwing in the towel in its bid for Canadian mining company Canplats Resources.Minera Penmont has said it will not be revising its bid after the Canplats board recommended the ‘superior proposal’ from bullion producer Goldcorp..Minera is offering C$4.20 in cash plus one share, with a notional value of C$0.20, in a new exploration company for every Canplats share. Goldcorp trumped those terms with a bid worth around C$4.80 a share, of which C$4.60 is being offered in cash.