Workers at Deere & Co. rejected a second contract offer, extending a strike against the farm equipment and construction machinery company that has lasted nearly three weeks.

Union employees at 12 Deere facilities voted against the tentative contract offer agreed to by their negotiators Oct. 30, the company said late Tuesday. Deere said that employees at two parts plants in Denver and Atlanta, who work under a separate contract, voted to approve the offer that had identical economic terms as the one that the company’s other employees rejected.