Domestic new-car sales fell 7.3 percent in mid-July compared with a year ago as General Motors Corp. continued to lose market share to Ford Motor Co. and Chrysler Corp., according to reports released yesterday.

Ford sales in the period were up 6.6 percent, and Chrysler's were up 3.3 percent. GM sales compared with a year ago were down 13.9 percent.

Ford, however, was off somewhat last year, which exaggerated this year's percentage gain. And Chrysler has been propping up its current sales with rebates on its compact K cars and special financing for its Le Baron GTS-Dodge Lancer sports sedans.

That led automotive analyst Joseph Phillippi at E. F. Hutton in New York to conclude that the softening market for new cars was not just a GM problem.

"They're all sliding," Phillippi said. "If we don't get some meaningful lift in the market soon, we're going to have to see some production cuts. Maybe not a lot, but there will have to be cuts."

Import sales are rising, Phillippi said, putting further pressure on the domestic auto makers. Importers report sales only once a month, so a comparison for the July 11-20 period cannot be made.

GM's market share was 55.4 percent, compared with 59.7 percent a year earlier. Ford was at 26.2 percent, compared with 22.8, and Chrysler was at 13.7, up from 12.3 a year earlier.

Other auto makers' results for mid-July:

American Honda, 3,603 vs. 2,733, up 31.8 percent; American Motors, 3,730 vs. 7,280, down 48.8 percent; Volkswagen of America, 1,816 vs. 2,216, down 18 percent; and Nissan USA, 989 vs. 0.