ORANGE COUNTY

Irvine-based Plessey Semiconductor, USA has promoted Bill Mathewson to national sales manager for North America. He had been western regional sales manager for the company for two years. Mathewson, 40, had been a district sales manager with Harris Semiconductors in Costa Mesa. before joining the firm. He replaces Jerry Surloff, who died in a plane crash in December. Plessey Semiconductor designs, manufactures, tests and packages large-scale integrated and hybrid circuits for electronics maufacturers.