WASHINGTON (AP) -- U.S. companies restocked their store shelves and warehouses at a steady pace in May, a sign they expect sales will remain solid in the months ahead.

The Commerce Department says business stockpiles rose 0.5% in May, down slightly from a 0.6% gain in the previous month. April's increase was the highest in six months. Total business sales rose 0.4%, much lower than April's 0.8% gain.

Steady inventory rebuilding can bolster economic growth by increasing demand for manufactured goods and boosting factory production. Still, sales need to remain healthy so that companies aren't stuck with unwanted inventories.

For May, inventories at the wholesale level climbed 0.5%, while inventories held by retailers ticked up just 0.2%. Stockpiles held by manufacturers rose 0.8%.