SEATTLE (AP) -- Despite a 48-hour contract extension, negotiations between Boeing Co. and Machinists union officials have failed and the union says a strike is set to begin at 12:01 a.m. PDT Saturday.

The talks broke off Friday, with the union sending out a message to members saying: "The strike is on!"

Boeing spokesman Tim Healy agrees the talks broke off. He says the company is open to further discussion, but both sides were too far apart to reach agreement.

"It is unfortunate that Boeing and the IAM could not reach a contract settlement acceptable to both parties," Wash. Govermor Christine Gregoir said. "I had hoped that the 48-hour extension would give both parties the opportunity to reach a speedy resolution. Boeing and its workforce are a critical part of the health of the state economy. I urge both parties to continue working on a resolution and settle the strike as quickly as possible. I will continue to monitor the situation closely."

The Machinists bargain for 25,000 aircraft assembly workers in the Puget Sound area and about 2,000 more in Wichita and Portland.

Workers voted this week to reject Boeing's contract offer and go on strike, mainly over job security. Both sides agreed to the extension at the request of Gov. Chris Gregoire.