The decline of U.S. medium- and heavy-duty truck sales continued in May.
Sales of trucks in classes 4 through 8 fell 15.2 percent in the month from a year earlier, to 29,657 units.
Sales of Class 4 and 6 dropped by more than a third from May 2007. Class 6 sales fell 35.3 percent to 3,256 units. Class 4 sales dropped 34.6 percent to 5,335. Sales of Class 7 trucks fell 12.2 percent to 4,935 units. Class 8 sales slid 6.2 percent to 11,400.
In contrast, Class 5 sales rose 17.8 percent in May to 4,731 units, the second straight monthly gain.
Through the first five months of 2008, sales in classes 4 through 8 fell 24.0 percent from the year-earlier period to 141,746.
For the month, Ford Motor Co. lost its spot as the market leader. International posted a 0.4 percent increase to 5,904 units. That was enough to pass Ford, whose May sales fell 38.3 percent to 5,756.
In year-to-date sales, Ford remains ahead of International. Ford's sales of 30,262 units through May are off 24.5 percent. International's sales of 29,339 are down 14.7 percent.
GMC's May sales rose 26.6 percent to 2,407 units. GMC sales through May are still down 2.2 percent to 6,884.