U.S. business inventories (search) grew by just 0.1 percent in May, somewhat less than expected, Commerce Department data showed Friday, while sales shrank by 0.1 percent.

Wall Street (search) analysts polled by Reuters had forecast a 0.3 percent rise in inventories compared with a revised 0.2 percent increase in April. This was initially reported as a 0.3 percent increase.

Economists see rising inventories either as a sign of confidence in future demand, or as a result of an unexpected decline in sales, which has led to involuntary stock building.

Deciding which of these interpretations is the case is helped by a sense of whether stocks are lean by historical standards from looking at the inventories-to-sales ratio (search).

This measure of the number of months it would take to deplete stocks at the current rate of sales was unchanged from April at 1.30 months, matching the record low first hit last year.

At a more detailed level within the report, retail inventories rose 0.2 percent in May while retail sales declined 0.3 percent.

Inventories at motor vehicle and parts dealers were down 0.6 percent and the motor inventory-to-sales ratio edged up to 2.0 months.

The Commerce Department said last week that wholesale inventories climbed just 0.1 percent in May.