Inventories increase 0.4% in March.

The Commerce Department said the increase was the biggest surge in stockpiles since a 0.5% rise last October. The government also reported that sales by U.S. businesses fell for the third consecutive month in March, by 1.6%. The combination of slumping sales and rising inventories could spell trouble for domestic manufacturers in the months ahead as businesses cut back on orders in an effort to reduce unwanted stockpiles.