AM General is laying off about 350 workers because of a cut in the number of Humvees it will make at its Mishawaka plant due to defense budget cuts and the drawdown of troops from Iraq and Afghanistan.
AM General CEO Charles Hall said the workers will be laid off in late October.
The Army had purchased more than 150,000 Humvees from AM General since 2000, but new production of Humvees for the Army ended in December 2010.
AM General announced in July it was building 808 Humvees and 744 armored troop enclosures for the vehicles for Afghanistan's military. The order was part of a contract the Pentagon awarded last year that calls for AM General to build up to nearly 12,000 Humvees.