Defense contractor BAE Systems PLC is laying off 300 employees, two-thirds of them at its plant in southern New Hampshire.

The company, headquartered in London, said Monday that affected employees will be notified by March 4.

About 4,600 employees work at the plant in Nashua, N.H. Other reductions in the 11,000-employee workforce will take place in Wayne, N.J.; Greenlawn and Endicott, N.Y.; Manassas, Va., and Austin, Texas.

The company said in a statement from its Electronic Systems business that the layoffs are a necessary response to changing staffing requirements and the overall economic climate for its industry.