300 More Convair Jobs Will Be Cut : Economy: The decision follows a recent announcement that 200 would lose their jobs. The moves are blamed on a slowdown in the jet airliner industry.

A slowdown in the jet airliner manufacturing business means General Dynamics’ Convair Division will lay off 300 more workers by the end of March, on top of the 200 layoffs announced by the division last month, the company said.

Convair, one of three General Dynamics units operating in San Diego, makes fuselages for McDonnell Douglas’ MD-11 commercial airliners. Until recently, Convair was delivering four to five of the aircraft bodies a month to McDonnell Douglas from its Lindbergh Field facilities.

But McDonnell Douglas recently informed Convair that it would begin accepting no more than three airplane bodies a month because of a slowdown in new orders. In December, Convair announced it would pare its work force by 200 to adjust to the reduced demand. Further review of manpower requirements this month led the division to decide it could deliver the bodies with 300 fewer employees.

“We look at production requirements and manpower requirements and adjust up or down as required, and at this time we felt we had to reduce the work force,” company spokesman Jack Isabel said Monday.

Of Convair’s 9,000 workers, about 3,000 are dedicated to the MD-11 fuselage program. Convair workers also make the Tomahawk sea-based cruise missile for the Navy and the air-launched Advanced Cruise Missile for the Air Force.

By the end of March, Convair’s payroll will have been reduced to 8,500.

The defense contractor’s local payroll has been dropping steadily over the past year, in part because of defense budget cutbacks. Overall, General Dynamics’ three divisions employ 15,600 locally, down from 17,900 at the end of last year. About 1,300 of the reductions came through the sale last fall of General Dynamics’ Data Systems Western Division.

General Dynamics’ other local operations are its Space Systems Division, which makes Atlas Centaur rocket boosters, and the Electronics Division, manufacturer of automatic test equipment.