Boeing said Monday it made a "best and final offer" to striking union machinists that includes bigger raises and larger bonuses than a proposed contract that was overwhelmingly rejected.

The company said the offer includes pay raises of 30% over four years, up from the rejected 25% raises.

It would also double the size of ratification bonuses to $6,000, and it would restore annual bonuses that the company had sought to replace with contributions to workers' retirement accounts.

Boeing said average annual pay for machinists would rise from $75,608 to $111,155 at the end of the four-year contract.

The company said its offer was contingent on members of the International Association of Machinists and Aerospace Workers ratifying the contract by late Friday night, when the strike will be a little over two weeks old.

The union, which represents factory workers who assemble some of the company's bestselling planes, did not immediately respond to a request for comment.

Boeing is offering workers upfront raises of 12% plus three annual raises of 6% each.

The new offer would not restore a traditional pension plan that Boeing eliminated about a decade ago. Striking workers cited pay and pensions as reasons why they voted 94.6% against the company's previous offer.

Boeing also renewed a promise to build its next new airline plane in the Seattle area -- if that project starts in the next four years. That was a key provision for union leaders, who recommended adoption of the original contract offer, but one that seemed less persuasive to rank-and-file members.

The strike is likely already starting to reduce Boeing's ability to generate cash. The company gets much of its cash when it delivers new planes, but the strike has shut down production of 737s, 777s and 767s.

On Friday, Boeing began rolling temporary furloughs of managers and nonunion employees and other money-saving measures. Those moves are expected to last as long as the strike continues.