Shares in engineer Charter International jumped after it revealed that Colfax, the US manufacturing group that was earlier this month named as a mystery bidder for Charter, is considering making a 910p a share offer.Colfax - which supplies fluid-handling products including pumps, fluid handling systems and controls, and speciality valves - gatecrashed rival engineer Melrose's offer for Charter last month. Melrose upped its bid for Charter to 850p from 840p earlier this month."Charter confirms that it is in advanced discussions with Colfax regarding a 910 pence per share offer for the Company, and expects these discussions to conclude shortly," Charter said today. "A further announcement will be made in due course."At 10.10am, shares in Charter International were up by 6% at 849p.---RG