CHICAGO, Jan. 3 (Xinhua) -- The big three American automakers -- General Motors (GM) and Fiat Chrysler Automobiles (FCA) reported sales decline in December, while Ford saw an increase compared with the previous year, according to official data released on Wednesday.

GM's U.S. sales fell 3.3 percent in December, and FCA's sales dropped 11 percent. Ford's December sales rose 0.9 percent, fueled once again by an encouraging 89,385 F-Series pickup trucks.

"F-Series had an unbelievable year as we sold nearly 900,000 pickups, with strong high-end truck demand as customers continue to opt for our latest technology and equipment packages," Mark LaNeve, Ford vice president of U.S. marketing, sales and service, said in a statement.

At GM, Cadillac declined 28.6 percent, Chevrolet was down 2.9 percent, while Buick sales rose 4.7 percent and GMC was up 1.2 percent on the strength of its Sierra pickup and Yukon full-size SUV.

At FCA, Jeep and Dodge posted declines of 12 percent and 23 percent respectively. Fiat brand sales fell 33 percent, while Ram slipped 3 percent, but still sold 44,907 pickup trucks.

Some of the decline can be attributed to FCA's decision to sale fewer vehicles to daily rental fleets. Across its five brands those fleet sales in December were down 42 percent from a year earlier, the company said in a release.

"December should be the biggest sales month of the year," Tim Fleming, analyst for Kelley Blue Book, said in a statement released before automakers reported the sales figures.

"It's also important to remember that December 2016 was the strongest month in nearly 15 years. We are projecting slower sales than last December."