DETROIT Chrysler LLC announced it will extend its month-long shutdown of its manufacturing operations at three plants in Belvidere, Illinois; Sterling Heights, Michigan; and Toluca, Mexico by one week, citing weak U.S. vehicle demand, according to Reuters.

The automaker's Belvidere plant builds the slow-selling Dodge Caliber, Jeep Patriot, and Jeep Compass SUVs, while its Sterling Heights factory builds the Sebring and Avenger sedans.

Chrysler began the month-long shutdowns of its 30 manufacturing facilities Dec. 19. By idling plants, Chrysler and other automakers can cut costs on inventory, components, and related charges such as utilities for operating large production facilities.