U.S. chain store sales grew modestly in January as retailers slashed prices to get rid of winter inventories, a report said Tuesday.

Sales at major U.S. chain stores grew 0.7 percent in the four weeks ended Feb. 1, compared with the same period last month, Instinet Research said in its weekly Redbook report.

Sales rose 1.8 percent in the week ended Feb. 1 compared with the same week a year ago, the report said.

"Retailers cautioned against misinterpreting sales gains, which are driven in January by end-of-season merchandise clearances," the report said.

The Redbook Average is compiled from a sample of general merchandise retailers representing about 9,000 stores. Same-store sales measure revenue at stores open at least a year.

The index is released weekly by Instinet Research, a division of Instinet, a Reuters-owned electronic brokerage.