By John S. McClenahen Consumer confidence in the American economy waned this month, although not by nearly as much as economists generally were expecting. The Conference Board's Consumer Confidence Index for March was 88.3 (1985=100), down only two-tenths of a percentage point from February's 88.5. A decline to 86.0 had been anticipated. Consumers felt better about business conditions in March than they had in February, but they also remained worried about the short-term future of the U.S. economy, two accompanying Conference Board indexes showed. Its Present Situation Index rose to 84.1 in March from 83.3 in February, while the Expectations Index dipped to 91.0 from 91.9. "While consumers claimed business conditions were more favorable in March than last month, they also claimed jobs were less readily available," relates Lynn Franco, director of the Conference Board's Consumer Research Center. "The labor market not only continues to dampen consumers' present-day spirits, but it is also making them less optimistic about the short-term outlook." Indeed, the percentage of consumers expecting business conditions to improve during the next six months edged down to 19.3% in March from 19.5% in February. Consumers claiming that jobs were hard to get increased to 30.0% from 28.9% in February. The Conference Board's monthly data are based on a representative sample of 5,000 U.S. households, and the survey is conducted by TNS NFO. Cutoff date for this month's survey was March 23. The Conference Board is a New York-based business research group.