DETROIT ? The traditional Big Three automakers retained their positions atop the U.S. industry in 2004, but record years for Japanese carmakers helped them chip away further at Detroit’s hold on the American automotive market.

General Motors Corp. and Ford Motor Co., the two largest U.S. automakers, reported lower U.S. sales in 2004 despite an onslaught of new vehicles, while DaimlerChrysler AG’s Chrysler Group rode the success of the popular Chrysler 300C sedan to the lone gain for the Big Three.

Kelly Pico, of Richmond, Va., looks over a new Toyota at a dealership in Richmond. Toyota's U.S. arm sold more than 2 million vehicles for the first time in its 47 years of existence as its sales grew 10 percent in 2004.

Meantime, the American arms of Toyota Motor Corp., Honda Motor Co. and Nissan Motor Co. sold more cars and trucks in the United States than ever before.

Toyota’s U.S. division sold more than 2 million vehicles for the first time as its sales grew 10 percent for the year. Chrysler, the smallest of Detroit’s Big Three, sold 146,000 more vehicles than Toyota last year. Chrysler’s edge in 2003 was roughly 260,000.

Honda’s 30-percent rise in sales in December helped propel the firm to its 11th consecutive year for a sales increase. With 1.4 million U.S. vehicle sales, Honda said business rose 3 percent in 2004.