FARGO, N.D. — More than 400 American Crystal Sugar Co. workers who have been locked out of their jobs for nearly two years returned to work Tuesday.

A little more than a month after the union ratified a new contract, some 400 workers returned to their jobs, Vice President Brian Ingulsrud said. About 1,300 sugar workers had been locked out of their jobs in North Dakota, Minnesota and Iowa since August 2011 after the union rejected a company contract offer.

“We’re glad to have our employees back,” Ingulsrud said. He said the union workers are evenly spread throughout the company’s factories.

A slight majority of union members voted to accept the company’s contract offer in April after rejecting the same terms four times before.

The company had said about 650 union employees had resigned or retired during the lockout.

A message left with the union was not immediately returned.