P.M. BRIEFING : Prime Computer to Lay Off 2,500

Prime Computer Inc. today said it will lay off 2,500 employees, or about 20% of its work force, due to a restructuring of the company into four units.

Prime was acquired in August for about $1.13 billion by New York investment firm J. H. Whitney & Co. after a protracted, nine-month battle for control of the Natick-based computer maker.

In a statement, Prime said the layoffs will occur mostly in the United States. Half of the U.S. layoffs, whose number was not specified, will be in Massachusetts, the company said.

Prime said it will be reorganized into four profit centers: the computervision business unit, the minicomputer business unit, the customer support business unit and the international business unit.

Prime posted a net loss of $18.9 million in the second quarter, compared with a $76.2 million profit in the same period last year.

Tustin, Calif.-based MAI Basic Four Inc. launched a hostile bid for Prime last November and the long battle cut into Prime’s earnings, sapped customer confidence and drove off some valued employees.