NEW YORK: US aviation giant Boeing has once again improved the terms of its contract offer to thousands of striking workers, hoping to end a painful strike that has paralyzed its two main factories for seven weeks .

The International Association of Machinists and Aerospace Workers, District 751, the union that represents more than 33,000 workers who went on strike Sept. 13 in the Seattle area, approved the new offer Thursday, Oct. 31, and set a vote for Monday.

The offer includes a 38 percent salary increase over the four years of the contract and a $12,000 sign-on bonus, up from $7,000 in the previous proposal, Boeing said in a separate statement.

“Your union supports and recommends the latest IAM/Boeing contract proposal. It is time for our members to consolidate these gains and declare victory with confidence,” the IAM section said.

This is the fourth offer made by Boeing since the beginning of September, but the third on which members are invited to vote.

On September 12, members overwhelmingly rejected an offer of a 25 percent increase over four years. A second offer, which promised a 35 percent pay rise, was rejected by almost two-thirds of members last week.

The union has always demanded a 40 percent wage increase.

“We believe that asking members to remain on strike for longer would not be a good thing given that we have had so much success,” the union said.

“We encourage all of our employees to learn more about the enhanced offer and vote on Monday, November 4,” Boeing said, noting that the average machinist will earn $119,309 by the end of the contract if the offer is accepted , compared to 119,309 US dollars. $75,608.

Other terms of the contract remain unchanged, such as an annual bonus, and the company’s commitment to build its next plane – expected in 2025 – in the Seattle area, where Boeing was founded in July 1916.

Union demands to restore a pension plan abandoned in 2014 have not been honored.