U.S. sales of medium- and heavy-duty trucks fell 22 percent in September from a year earlier to 20,009 units, continuing a nearly three-year slide in large-truck sales.
For the first nine months of 2009, truck sales dropped 33 percent to 165,112.
Truck sales have fallen every month since January 2007.
Ford Motor Co. led all truckmakers in September. Its sales dipped 8 percent to 5,228.
Second place went to International, whose sales fell 21 percent to 4,499.
Freightliner was third. Its sales dropped 27 percent to 3,537.
Sales fell for all size categories.
Class 7 sales held up better than the others, off just 3 percent to 3,428.
Class 8 sales tumbled 29 percent to 7,769, and Class 6 sales fell 30 percent to 2,000.
Class 4 sales slid 17 percent to 4,999.
Class 5 sales dropped 25 percent to 1,813.