Oct 8 (Reuters) - Boeing ( BA ) said on Tuesday that it

had withdrawn its pay offer to around 33,000 striking U.S. West

Coast factory workers and no further negotiations were planned

with their union representatives.

"Unfortunately, the union did not seriously consider our

proposals," Boeing Commercial Airplanes head Stephanie Pope said

in a note to the employees, calling the union's demands

"non-negotiable".

"Further negotiations do not make sense at this point and

our offer has been withdrawn."

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 International Association of Machinists and Aerospace

Workers union said in a statement that Boeing ( BA ) was "hell-bent on

standing on the non-negotiated offer" proposed last month.

"They refused to propose any wage increases, vacation/sick

leave accrual, progression, ratification bonus, or the 401k

Match/SCRC Contribution. They also would not reinstate the

defined benefit pension," it said.