(fxcue news) - Aerospace giant Boeing Co., which has been hit by an ongoing strike by machinists, has come out with its improved "best and final offer" with a larger pay hike and bonuses, urging the employees to ratify by September 27. Meanwhile, Boeing's largest union, The International Association of Machinists and Aerospace Workers or IAM, declined to put the offer to a vote, noting that it was not negotiated with the union, and that it fails to meet their demands and creates divisions among the workers. Boeing, after months of negotiations, had reached a tentative agreement on September 8 with IAM Districts 751 & W24, and the union also recommended acceptance of the deal, because they couldn't guarantee of achieving more in a strike. But, soon after, the company's about 33,000 machinists union members rejected the proposed four-year contract and started a strike in the airplane assembly at Boeing's factories in the Seattle area as well as in Portland, Oregon and in southern California on September 13rd, seeking better pay and benefits. The planemaker, in its website, now updated that it has made significant improvements in the final offer to provide more money in key areas, following feedback from the employees. The company now offers pay raises totaling 30 percent over four years, higher than the initial offer of 25 percent. Meanwhile, the latest offer is lower than the union's demand of 40 percent. Further, Boeing has doubled the ratification bonus to $6,000, and reinstated an annual productivity bonus, which was not included in the orignal offer. The company also increased company match on Boeing 401(k) to 100 percent of first 8 percent of pay, plus continuing automatic 4 percent company contribution. Initially, it was 75 percent of 8 percent of pay, plus automatic 4 percent company contribution. All other terms of the Tentative Agreement stay the same. Boeing also said the offer is contingent on ratification by 11:59 p.m. PT on September 27. Responding to Boeing's final offer, the Union Negotiating Committee of IAM, in a Facebook post on the 11th day of the strike, alleged that the offer was not negotiated with the Union and that the company disrespected them by sending the offer directly to all members and the media without any prior communication from the Union. The union said, "Your Negotiating Committee did not have any discussion or input on this offer. We have said all along that the Union would be available for direct talks with Boeing or, at a minimum, expected to continue mediated discussions when the company was ready. These direct dealing tactics are a huge mistake, damage the negotiation process, and attempt to go around and bypass your Union negotiating committee." The union noted that mediation broke down on September 18 after the company refused to make an offer that addressed the priorities of union membership. The union further said it will not be voting on the 27th as the final given date for voting does not give enough time to present details to the membership or even secure all voting locations. IAM also alleged that Boeing is trying to drive a wedge between union members and weaken its solidarity with this divisive strategy, and that the firm misled the media by wrongfully stating the Union membership is required to vote on their latest offer. Meanwhile, Boeing reportedly said it first presented the offer to the union and then transparently shared the details with employees. The strike, the first at the firm since 2008, has hit the commercial airplane production of the aircraft manufacturer, which is already struggling with its various plane safety issues. Amid the developments, Boeing was planning various cost-cutting measures, including hiring freeze, cut in supplier spending and possible temporary furloughs, to meet the strike impact.