Boeing (NYSE:BA) is confronting a fresh labor disruption as about 3,200 unionized workers at its defense facilities in the St. Louis region walked off the job after rejecting the company's latest contract offer.

Union members who assemble Boeing's fighter jets in the St. Louis area rejected the U.S. planemaker's latest contract offer on Sunday and will strike at midnight on Monday, the International Association of Machinists and Aerospace Workers union (IAM) said.

Boeing workers who build fighter jets are planning to go on strike Monday at midnight. About 3,200 workers at Boeing facilities in St. Louis; St. Charles, Missouri; and Mascoutah, Illinois, voted to reject a modified four-year labor agreement with Boeing,