Wholesale inventories rose 1.4% in July, the Commerce Department said Tuesday.
The increase followed a revised 0.9% increase in June, Commerce said.
The gains were led by automobiles, machinery and petroleum, as wholesale sales fell 0.3%.
The inventory reading was higher than the 0.7% increase forecast by economists, Bloomberg reported.
Wholesale inventories account for about a fourth of total business stockpiles, while retailers and factories account for the rest.