WASHINGTON, (Reuters) - - U.S. wholesale inventories in September rose slightly less than previously reported, the Commerce Department said on Wednesday.

Inventories edged up 0.1 percent during the month, the department said.

The department's monthly advance economic indicators report published last month had estimated that wholesale inventories rose 0.2 percent in September, as did economists polled by Reuters.

The component of wholesale inventories that goes into the calculation of GDP - wholesale stocks excluding autos - increased 0.4 percent in September.

Inventory investment added 0.61 percentage point to economic growth in the third quarter after having dragged heavily on growth in the April-June period.

Sales at wholesalers rose 0.2 percent in September.

At September's sales pace it would take wholesalers 1.33 months to clear shelves, unchanged from August.

(Reporting by Lindsay Dunsmuir; Editing by Andrea Ricci)