SEATTLE :Boeing shares gained 3.5 per cent on Friday on bets that the planemaker's U.S. West Coast factory workers will approve a new wage offer and end a seven-week strike that has halted jet production and hammered the company's finances. Around 33,000 machinists, who have been on strike since Sept. 13, will vote on Monday on a new contract offer raising wages by 38 per cent over four years, up from a prior 35 per cent offer. The proposal adds a $12,000 ratification bonus but did not meet