WASHINGTON - U.S. wholesale inventories increased in March amid flat sales, confounding the government’s initial estimate of a modest dip.

FILE PHOTO: Workers stock shelves in a newly built Walmart Super Center prior to its opening in Compton, California, U.S., January 10, 2017. REUTERS/Mike Blake

The Commerce Department said on Tuesday wholesale inventories rose 0.2 percent after increasing 0.3 percent in February. The department reported last month that wholesale

inventories slipped 0.1 percent in March.

Auto inventories increased 1.9 percent. Wholesale stocks of electrical goods surged 2.3 percent, the biggest gain since January 2015. Professional equipment inventories rose 1.0 percent in March.

The component of wholesale inventories that goes into the calculation of gross domestic product - wholesale stocks excluding autos - were unchanged in March.

A report last week showed inventories at factories were flat in March after rising 0.2 percent in February.

Inventory investment subtracted 0.93 percentage point from GDP in the first quarter, helping to hold down the economy to a 0.7 percent annualized growth pace, the weakest performance in three years. Inventories had contributed to GDP growth for two

straight quarters.

Sales at wholesalers were unchanged in March after climbing 0.7 percent in February. Sales of electrical goods fell 0.3 percent while those of professional equipment tumbled 1.8 percent.

At March’s sales pace it would take wholesalers 1.28 months to clear shelves, unchanged from February. The ratio has declined from 1.36 months in January and February last year, which was the highest since January 2009.