Boeing and striking union negotiators to return to the table on Monday

(Reuters) -Boeing's largest union said on Friday that contract talks will resume on Oct. 7, as both sides seek an agreement that would put an end to a strike by around 33,000 of the planemaker's U.S. West Coast factory workers.

Negotiators for the U.S. planemaker and its largest union have struggled to find common ground, recently failing to clinch an agreement on key issues in the presence of federal mediators.

Reaching a deal with the International Association of Machinists and Aerospace Workers that would end the stoppage is a priority for Boeing, as it wrestles with mounting debt, worsening cash burn and the threat of losing its investment grade rating.

The IAM's district 751, which is negotiating the deal, said in a post on X that it would resume talks with Boeing on Monday with assistance from federal mediators.

"This meeting is another critical opportunity to push for the priorities of our membership," the union said.

Boeing confirmed that negotiations would resume Oct. 7. The talks have attracted attention from U.S. President Joe Biden's administration, with acting U.S. Labor Secretary Julie Su and her staff continuing to engage with both parties, a spokesperson said.

The strike has halted production of Boeing's 777, 767 and its best-selling 737 MAX jet. The MAX is a key revenue-driver for the company at a time when it is struggling with weak margins in its defense business.

The strike, Boeing's first since 2008, is the latest event in a tumultuous year for the company that began with a January incident in which a door panel detached from a new 737 MAX jet during a flight.

Boeing recently made a "best and final" pay offer featuring the reinstatement of a performance bonus, improved retirement benefits and doubling of its ratification bonus to $6,000, but union leadership declined to put it to a vote.

An earlier tentative deal between Boeing and the union that offered a 25% raise over four years and a commitment that a new plane would be manufactured in the Seattle area if it were launched during the four-year agreement was voted down by more than 90% of workers in September.

Boeing shares were up 2.1% in afternoon trading on Friday.

(Reporting By Allison Lampert, David Shepardson and Mike Stone; Editing by Bill Berkrot)