KANSAS CITY — American Crystal Sugar Co. locked out about 1,300 employees at its facilities Monday after union workers rejected a five-year contract offer to replace an agreement that expired Aug 1.

About 93% of Local 167G of the Bakery, Confectionery, Tobacco Workers and Grain Millers voted Saturday to reject the company’s offer, voicing concerns over health care and job security, according to reports on The Forum of Fargo-Moorhead web site.

The company’s offer was based on a $75,000 annual pay and benefits package, with pay increasing 8% the first year and 9% over the remaining four years of the contract, in addition to increased pension fund payments and vacation days, according to the reports. Among other terms, the contract required union employees to transition to the same health insurance plan as other employees as of Jan. 1, 2012, which the union indicated would be too costly for its members.

American Crystal operates five sugar beet processing plants in the Red River Valley and two additional facilities in the Upper Midwest. The company said it would not allow the union to work without a contract and risk a strike as the sugar beet harvest approaches in September and processing gears up for fall. The company indicated it would use non-union workers to keep facilities running if necessary.