Brunswick Corp. said Wednesday it plans to...

Brunswick Corp. said Wednesday it plans to sell its San Diego-based Advanced Materials Technology Center, a unit of its defense division that is involved in the development of so-called Stealth aviation technology.

Brunswick’s AMTC facility employs 40 people in a 30,000-square-foot plant in the Miramar Road area, general manager Ray Buttram said. The unit is being sold because the development of its technology requires an investment that is not “compatible” with the company’s other businesses, Buttram said.

Based in Skokie, Ill., Brunswick is best-known as a manufacturer of pleasure boats and marine engines. The company’s other San Diego operation, called BioTechnetics, is researching therapeutic and commercial applications of monoclonal antibodies.