Businesses added to their stockpiles for a 16th consecutive month in April. But their sales grew at the slowest pace in 10 months, a sign that many companies could be forced to slash supply levels soon if the economy weakens further.

The Commerce Department says business supply levels grew 0.8 percent in April and sales rose for a 10th straight month. But the 0.1 percent sales increase was the smallest since sales fell 0.5 percent in June of last year.

The concern is that with the economy slowing, businesses may have miscalculated on consumer demand and could be stuck with unwanted inventories. That would trigger cutbacks in orders and cause manufacturing activity to slow.