General Motors Corp. Tuesday posted a 4% drop in March U.S. light-vehicle sales as retail sales fell and the world's largest auto maker continued to slash sales to rental-car fleets.

Ford Motor Co.'s sales fell 9%, but the auto maker said its market share appears to be "stabilizing." Chrysler Group, meanwhile, reported a 4.6% drop, while Toyota Motor Corp.'s sales jumped 12%.

GM also cut second-quarter North American production forecast, but raised its first-quarter production forecast for Europe and the Asia-Pacific region.

GM sold 345,418 light vehicles in March, compared with 359,705 vehicles a year earlier. In March, GM North America produced 401,000 vehicles, down 59,000 vehicles, or 13%, from a year ago.

GM revised its second-quarter North American production forecast at 1.16 million vehicles, down 1.3% from last month's outlook. The company had forecast second-quarter North American production of 1.175 million vehicles.

For Europe, GM raised its first-quarter production forecast to 511,000 vehicles, up 3,000 from last month; and boosted its second-quarter target to 473,000 vehicles, up 6,000 from the prior month.

For Asia Pacific, the auto maker raised its first-quarter production estimates to 539,000 vehicles, up 1,000 from last month; and raised its second-quarter forecast to 568,000 vehicles, up 8,000 from last month.

For Latin America, Africa and the Middle East, GM lowered its first-quarter production forecast to 222,000 vehicles, down 3,000 from last month's guidance. The region's second-quarter production forecast was left unchanged at 233,000 vehicles.

There were 28 selling days last month, versus 27 days in March 2006.

Ford Sales Slide

Ford said sales of the No. 2 auto maker's F-Series pickup truck, one of its most profitable vehicles, dropped 15%. Passenger-car sales fell 15% while sales of trucks and sport utility vehicles -- representing Ford's most profitable business -- were down 5.8%. Ford, Dearborn, Mich., sold 264,975 cars and light trucks in March, compared with 291,146 a year ago.

Ford's president of the Americas, Mark Fields, said the company is "moving quickly to operate profitably at lower volumes and a changed mix, and we are encouraged our retail market share appears to be stabilizing over the past several months."

"Our newest products also are achieving the sales targets we have set for ourselves, another sign that we're making good progress," Mr. Fields said.

Earlier this year, Ford posted the largest full-year loss in its history, a shortfall of $12.7 billion for 2006. It posted consecutive double-digit percentage drops in sales of cars and light trucks in each of the first two months of this year -- 13.5% in February, and 19% in January.

Toyota said March sales of cars and light trucks in the U.S. jumped 12% amid strong sales of its Toyota and Lexus hybrid vehicles. The Japanese auto maker said it sold 242,675 vehicles in March, compared with 217,286 a year ago.

DaimlerChrysler AG's Chrysler posted total sales of 206,435 vehicles for the month -- the first time it topped the 200,000 mark in monthly sales since posting sales of 216,412 in March 2006. The German parent company's luxury Mercedes-Benz USA division, on the other hand, posted a 0.9% rise in March sales.

The big Detroit auto makers -- GM, Ford and Chrysler -- have been reducing sales to rental-car fleets, which carry low profit margins, to concentrate on more lucrative sales to customers at dealerships. The move stems from an overall shift by buyers away from trucks and sport-utility vehicles toward more fuel-efficient vehicles, mostly built by Asian companies.

Generally, analysts expect a modest volume increase in March U.S. auto sales to usher in what is a traditionally strong selling season and to break a three-month industry slump during which sales fell 3%.