Business inventories rose 0.1% in June, the Commerce Department said Tuesday.
The gain followed a 0.3% increase in May.
Sales fell 1.1%, the largest decrease since March 2009.
Economists had projected a 0.2% rise, Bloomberg reported.
Factory inventories, which make up about two-fifths of the total, increased 0.1%, but wholesale inventories, which make up about 30%, fell 0.2% in June.
When sales are growing, it usually means trucking is seeing additional demand to deliver goods and restock shelves.