British engineer Charter International has rejected investment firm Melrose's revised 840p-a-share bid, saying that the proposal undervalues the company and its prospects.Charter maintains that the sweetened offer does not reflect, among other things, the belief that the market was undervaluing the company's prospects in the immediate aftermath of its trading statement on 20 June. On 20 June, Charter had warned that full year figures are expected to be below forecast and announced further cost cutting, which had wiped off more than 21% from its market value. Charter's board reaffirmed its confidence in the ability of its core ESAB welding and metal-cutting wing to effect substantial operational improvement under the new management team and added that it is exploring a full range of strategic alternatives to maximise shareholder value.Shares of Charter rose 0.4% to 832p, while Melrose was up 0.2% at 360p in London.AR