Oct 7 (Reuters) - Boeing's ( BA ) largest union said it

would continue negotiations with the planemaker on Tuesday, as

both sides seek an agreement to end a strike by around 33,000

U.S. West Coast factory workers.

The company and the union, whose members have been on strike

for 25 days, had resumed contract talks on Monday in the

presence of federal mediators.

"Although we met with Boeing ( BA ) and federal mediators all day,

there was no meaningful movement to report. We will be back at

it tomorrow," The International Association of Machinists and

Aerospace Workers said late on Monday.

Boeing ( BA ) did not immediately respond to a request for comment.

The union is seeking a 40% pay rise over four years and the

restoration of a defined-benefit pension that was taken away in

the contract a decade ago.

Boeing ( BA ) made an improved offer last month that it described

as its "best and final", which would give workers a 30% raise

and restore a performance bonus, but the union said a survey of

its members found that was not enough.

The strike has halted production of Boeing's ( BA ) best-selling

737 MAX jet, along with its 777 and 767 widebody planes. The MAX

is a key revenue-driver for the company at a time when it is

struggling with weak margins in its defense business.