Summary Box: Business stockpiles rose in May

STOCKPILES RISE: Business supply levels grew 1 percent in May, marking the 17th consecutive monthly increase, according to the Commerce Department.

SALES FALL: Sales fell for the first time in 11 months. Economists worry that businesses may have miscalculated consumer demand. That would leave them stuck with unwanted inventories and could lead to a cutback in orders.

CONTRIBUTION TO ECONOMY: Analysts say weak sales could mean business supplies will make a very small contribution to economic growth in the April-June quarter.