DETROIT ? The top three U.S. automakers posted a 4 percent drop in sales last year after a robust 2001, but all had strong business in December thanks to attractive financing deals and other incentives.

No. 1 General Motors Corp. said Friday that it sold 4.78 million cars and trucks in 2002, down 1 percent from 2001’s 4.8 million. No. 2 Ford Motor Co. was off 10 percent for the year, while DaimlerChrysler AG’s Chrysler Group had a 3 percent decline in total sales.

Industrywide, total U.S. light vehicle sales of 17.2 million in 2001 made it the second-best year on record. The 2002 forecast is for 16.5 million cars and trucks — possibly the fourth-best total.

However, much of the volume in 2002 was fueled by profit-shrinking incentives, and serious questions linger about prospects for sales in the coming months.

GM, Ford and Chrysler sold 923,299 light vehicles last month, 21 percent higher than the year-ago period.Boosted by hefty incentives to meet year-end market-share goals, GM sold 466,875 vehicles in the United States last month, an increase of 36 percent from December 2001.

GM’s sales figures exclude those for its foreign brand Saab, which saw sales rise 5 percent in December and 1 percent for the year.

“GM had an excellent year in 2002 on all fronts — all leading to market-share gains and an increased customer base,” said John Smith, the company’s group vice president for North American sales, service and marketing.

Ford’s sales of Ford, Lincoln and Mercury brands totaled 3.4 million last year, compared with 3.76 million in 2001. Excluding foreign brands, Ford’s December sales rose 14 percent, slightly higher than some analysts’ predictions.

Bob Lutz, General Motors Corp.'s vice president for product development, speaks to media about the new Pontiac GTO. GM unveiled the new GTO Friday in Los Angeles. Automakers suffered through poor sales throughout most of 2002 but were buoyed by strong sales, helped by attractive buyer incentives, in December.

Merrill Lynch analyst John A. Casesa had predicted Ford’s December sales to increase about 10 percent as it tried to keep up with GM.

Ford said its F-Series trucks were America’s best-selling vehicles in 2002 with sales of 813,701. It marked the 21st year in a row that Ford’s full-size line of pickups topped the U.S. sales charts and the fifth year in a row that sales exceeded 800,000.

Ford also said it was increasing its first quarter 2003 North American production plan by 10,000, to 1.01 million vehicles, because of higher than expected December sales.

Chrysler’s December sales were up 1 percent — in line with Casesa’s forecast. The company’s Jeep brand had sales of 45,751 in December, a record for the month. The company’s popular Dodge Ram pickup also set a December record with 34,812 units sold.

Shares in GM dropped 41 cents to close at $38.54 each, Ford fell 26 cents to close at $9.58 and DaimlerChrysler AG’s U.S. shares lost 83 cents to close at $32.14 on the New York Stock Exchange.

Total vehicle sales at Toyota Motor Sales USA Inc., including the Toyota and Lexus brands, rose 2 percent last month and were up 1 percent for the year. Toyota said its Camry became the best-selling car in America for the fifth time in the past six years, with 434,145 units sold, surpassing last year’s top seller, the Honda Accord.