HERNDON, Va. — Volkswagen of America Inc. said today that December U.S. sales of its namesake brand vehicles fell on steep drops in demand for nearly all of its models.

Volkswagen sold a total of 17,577 vehicles in December, down 14.4 percent from 20,543 in the same month of 2007. Sales of Jetta models fell a combined 9.8 percent to 8,063 units while Passat sales slid 20.7 percent to 2,532.

For the full year, Volkswagen brand sales dropped 3.2 percent to 223,128 vehicles from 230,572 in 2007.

Separately, Audi of America, the company’s luxury U.S. division, said its December sales dropped 9.3 percent to 7,712 vehicles from 8,504 in December 2007. Sales of its A4 model fell 8.2 percent to 3,854 units.

For the full year, Audi said its sales fell 6.1 percent to 87,760 vehicles from 93,506.