The Commerce Department said four companies have been selected for the Malcolm Baldrige National Quality Award for 1990.

The winners are: The Cadillac Motor Car Division of General Motors Corp., Detroit; International Business Machines division, Rochester, Minn.; Federal Express Corp., Memphis; Wallace Co. Inc., a private Houston petrochemical firm.The award, named for the late Reagan administration commerce secretary, recognizes American companies that practice and promote quality and share successful quality management strategies with others.

Commerce Secretary Robert Mosbacher, saying top-notch exports are the key to the nation's business future, called quality "the one thing we can do in this country to assure our continued economic prosperity."

"If we can keep up our exports, it'll keep us out of any real recession," Mosbacher said. "The No. 1 way you build your exports is building quality products. It sounds simple as hell, but that's the way it is."

The award judges, including business school faculty and retired corporate executives, checked 97 competing companies on customer satisfaction, planning, quality assurance, leadership and other points.

The selection of Federal Express marks the first time a services-sector company has earned the award. Cadillac and IBM were cited for achievements in manufacturing. Wallace was cited for achievements as a small business.

In 1989, Milliken & Co., and Xerox Business Products and Systems were named winners. In 1988, the first year the competition was held, Motorola Inc., the commercial nuclear fuel division of the Westinghouse Electric Corp., and Globe Metallurgical Inc., claimed the award.