AEROSPACE & DEFENSE

Electronics Plant to Close: GEC-Marconi Electronic Systems Corp. will close its San Marcos, Calif., plant in 1994, putting 375 people out of work because of defense cutbacks, officials said. After more than 30 years of operation, the plant is scheduled to close in March or April of next year, company officials said. GEC-Marconi, based in Wayne, N.J., made the decision to close its West Coast plant because of a decline in military contracts. GEC-Marconi depends 100% on military orders for its aircraft computers, navigation equipment and communications systems.