CHAMBERSBURG — A military repair depot in central Pennsylvania has announced plans to lay off or reassign hundreds of contract employees due to an anticipated decrease in workload.

Letterkenny Army Depot said the reduction will affect 323 contract personnel, nearly half of its contract positions. Up to 75 positions will be cut on or about March 10, and up to 248 additional workers will lose their jobs by September, although some workers could be reassigned.

Officials said the reduction will affect about 15 percent of its total workforce of approximately 2,200 employees. Spokeswoman Lisa Baker said nearly one-third of all employees are contract personnel, while the others are federal employees.

Letterkenny, which is north of Chambersburg, is one of Franklin County’s top employers, with workers repairing tactical missile systems, route clearance vehicles, electrical generators and other items. Letterkenny Munitions Center on the depot stores rockets and ammunition.

Letterkenny Army Depot Commander Col. Gregory Gibbons said officials recognize the contractors’ contribution to Army readiness and the depot “would not be able to operate without them.”