SEATTLE -- Workers in Boeing's Machinists Union officially went on strike at 12:01 a.m. after last-minute efforts between union and company negotiators failed to reach a labor agreement.

In a posting on the Machinsts District 751 Web site Friday, District President Tom Wroblewski said of Boeing, "This Company disrespected the process, bargained illegally and most of all, disrespected the finest aerospace workers anywhere on the planet by failing to meet your expectations."

"Despite meeting late into the night and throughout the day, continued contract talks with the Boeing Company did not address our issues. Armed with your strong strike vote, the IAM Negotiating Committee continues to try and convince the Company to meet our members’ demands."

The contract affects 25,000 aircraft workers in the Puget Sound area and about 2,000 more in Wichita and Portland.

Workers voted earlier this week to reject Boeing's offer and authorized a strike, mainly over job security, but union leaders agreed to a 48-hour contract extension at the request of Gov. Chris Gregoire.

The talks broke off Friday afternoon, more than eight hours before the extension officially expired.

Boeing spokesman Tim Healy said the company is open to further discussion, but both sides were too far apart to reach agreement.