Unionized workers have gone on strike at some Chrysler plants in the United States, after negotiators failed to agree on a new contract before a union-imposed deadline.

Some plants continued working after the deadline Wednesday, but workers set up picket lines outside several Chrysler factories in Michigan.

Chrysler Auto Workers Begin Strike

Last month, union employees staged a two-day strike at the largest U.S. automaker, General Motors. The contract agreement the union reached with G.M. was to be used as a template for contracts with Chrysler and Ford.

Chrysler Auto Workers Begin Strike

The General Motors deal included creation of a company-funded, union-run trust fund for retiree health care.

Chrysler Auto Workers Begin Strike

U.S. auto companies have been trying to cut costs so they can better compete with Asian automakers who have been taking a larger share of the car buying market.