BAE Systems yesterday said it has agreed to acquire OASYS Technology, a small company specializing in the design and manufacture of electro-optical systems and subassemblies for aerospace, defense, industrial and commercial markets.

Terms of the deal, which is expected to close in the fourth quarter of 2010, were not disclosed.

OASYS, which is based in New Hampshire, makes various systems including helmet-mounted displays, thermal clip-ons, monoculars, binoculars, and compact multispectral systems. OASYS has capabilities in lower size, weigh, power and cost thermal imaging products that will complement BAE’s existing capabilities to better support its customers.

“OASYS Technology’s talented workforce and technologies will enhance BAE Systems’ ability to serve its customers as a leader in day/night surveillance and targeting systems as well as precision guidance,” Bob Murphy, executive vice president of BAE Systems, Inc. Product sectors, said in a statement. BAE Systems, Inc., is the United States-based division of Britain’s BAE Systems.

OASYS has 65 employees at its 40,000 square foot design and manufacturing facility.