Ford's U.S. sales dropped 21 percent in September over August and 39 percent year over year, the manufacturer reports. Sales of Ford's F-150 pickup fell 21 percent last month.

Ford said it reduced sales to rental fleets by 62 percent. George Pipas, Ford's sales analyst, said Ford expects to cut sales to daily rental fleets by 135,000 vehicles, more than its original goal of 30 percent this year.

Pipas said the planned sales reductions to rental would be so great that Ford would incur a sales decline every month this year, the Associated Press reports.

General Motors Corp. reported flat sales compared with last September. Chrysler LLC said its U.S. sales fell 5 percent, although retail sales were up and fleet sales were down year over year.