Corporate Data Sciences, a Manhattan Beach holding...

Corporate Data Sciences, a Manhattan Beach holding company, has cut its stake in Marcom Telecommunications Inc., a West Palm Beach, Fla., telecommunications concern, to 41% from 51% and is looking to sell the remainder of its stake. U.S. Alcohol Testing of America Inc., Dayton, N.J., will use the proceeds of a $300,000 stock sale to buy out Luckey Labs Inc., a San Bernardino-based company that makes breath analyzers . . . Tweedy, Browne Co., a New York investment concern, has increased its stake in Sprouse-Reitz Stores Inc., a Portland, Ore., variety store chain, to 11.71% from 8.84% . . . The Federal Reserve said the average yield for one-year T-bills, the most popular index for making changes in adjustable-rate mortgages, fell to 7.85% last week from 7.97% the previous week . . . Baker Hughes Inc., Houston, reports that a lengthy drilling spurt stumbled slightly this week as the number of oil and gas rigs working in the United States dipped by five to total 820.