U.S. wholesale inventories grew more than expected in January as they logged their largest monthly increase in six years, the latest data from the U.S. Census Bureau showed.

Inventories held by merchant wholesalers, excluding manufacturers' sales branches and offices, rose 1.2%, to a seasonally adjusted $669.87 billion in January from the revised $662.04 billion in December 2018.

Econoday had projected that wholesale stockpiles would edge up 0.1% month over month in January.

The latest monthly gain in inventories was the biggest since September 2012, when inventories also climbed 1.2%.

Sales of merchant wholesalers went up 0.5%, to $499.82 billion in January from $497.51 billion in the previous month.