SOUTH BEND – AM General said it plans to lay off 400 employees at its military assembly plant in northern Indiana beginning Jan. 1.

Company spokesman Jeff Adams told the South Bend Tribune (http://bit.ly/VGoJUr) that the layoffs announced Thursday will last until March.

Adams said such temporary layoffs may become more common in the future. He said the company had hoped to have a new international contract ready for 2013, but it has been delayed.

Workers at the Mishawaka plant that makes Humvees for the military had returned to work Nov. 26 following a layoff of nearly two months.