Chrysler reported Tuesday it posted its best U.S. auto sales in April since 2008, while sales for General Motors (GM) and Ford, two other big American automakers, were revealed as down eight percent and five percent in the past month, respectively.

Chrysler Group LLC notched up U.S. sales of 141,165 units in April, a 20 percent increase from the same period last year, which marks the automaker's eleventh consecutive month of year-over-year sales gains.

Leading Chrysler's sales increases was the group's Fiat brand, which posted a whopping 336 percent year-over-year sales gain in the past month, a record high. Chrysler brand sales were also strong, with the year-over-year sales increase of 56 percent, making it the brand's best April since 2007.

In addition to the Fiat 500, four other Chrysler models also set sales records in April, including the Chrysler 200 sedan, Dodge Challenger and Jeep Wrangler. The Dodge Avenger in particular posted a 47 percent sales gain, which was an all-time sales record.

The April sales release comes around one week after Chrysler released its 2012 first quarter profits, which at 473 million U.S. dollars was the company's strongest performance in 13 years.

April sales at competitors GM and Ford were not as successful as Chrysler, as the rest of the Big Three U.S. automakers posted year-over-year sales declines.

Ford sold 180,350 vehicles in the United States in April, down five percent from the 189,778 achieved a year ago.

Although Ford models Fusion and Edge set April sales records and Ford Focus sales were up 13 percent for the month, Ford was somewhat dragged down by poor performances from other brands of motor vehicles.

The Ford Fiesta and Escape models were down 43.9 percent and 20 percent year on year, respectively, while the Lincoln brand as a whole was down 12.8 percent.

Recent higher gas prices in the United States have received increased public attention, and Ford noted that the company continued to see strong demand for fuel-efficient vehicles. Ford said that it saw a 77 percent increase in vehicles with its EcoBoost engines in April, mainly in the strong-performing Fusion and Focus brands.

Meanwhile, GM sold 213,387 vehicles in the United States in April, an eight percent decline year on year.

According to GM, its U.S. retail sales in April were essentially equal to that of last year, but due to the timing of rental customer deliveries, GM's fleet sales were down 25 percent, leading to the eight percent total decline.

GM's GMC brand led sales increases in April, and was up 4.4 percent from a year ago. The Cadillac brand posted the sharpest retail sales drop, down 11.4 percent from the same time last year.

Retail sales of GM's Chevrolet brand were essentially flat compared to that of last year, with a year-on-year increase of 0.2 percent. If this April's three missing calendar sale days were factored out of the equation, however, Chevrolet cars would have posted a retail sales year-on-year gain of 12.7 percent, according to GM.

GM said it remains optimistic regarding the outlook of the U.S. auto industry going forward, and taking into consideration the strong first quarter growth it revised its industry forecast for the year 2012 U.S. auto sales up to 14 to 14.5 million vehicles.

According to research group Autodata Corp, U.S. auto sales totaled 12.8 million in 2011.

"We expect gradual improvement in the economy going forward," said Don Johnson, Vice President of GM U.S. Sales Operations.

"Over time, strength in the manufacturing sector and strong retail sales will lead to more job creation. That will help more consumers put the recession behind them, gain even more confidence and drive vehicle sales higher for both the industry and GM," Johnson said.

The U.S. auto industry was hard-hit following the 2008 financial crisis, with both GM and Chrysler filing for bankruptcy. The two were later bailed out by the U.S. federal government.