Sales at U.S. retail stores remained strong in the first week of February as another potential sign that the economy is edging its way out of recession, two separate reports showed on Tuesday. 

The Bank of Tokyo-Mitsubishi and UBS Warburg reported in their Weekly Chain Store Sales Snapshot that U.S. chain store sales rose 2.1 percent during the week ended Feb. 9, after a 0.7 percent drop in the prior week. 

Meanwhile, Instinet Research's Redbook Retail Sales Average rose 0.9 percent in the week ended Feb. 9 compared with the same period last month. Year-over-year sales rose 4.2 percent, as did month-to-date sales compared to February 2001. 

"A pickup in customer traffic helped to propel discounters' sales, and less weakness in mall traffic also helped to moderate the sales weakness at department stores," the BTM report said. 

Compared with the same week last year, the index grew 4.1 percent, the strongest reading in almost a year and well above the prior week's 2.8 percent year-over-year gain. 

The BTM/UBSW Weekly Chain Store Sales Snapshot is compiled from seven major discount, department and chain stores across the country that report their weekly results. 

Those stores include J.C. Penney, Sears, Target, Kmart, Wal-Mart, Federated Department Stores Inc. and May Department Stores Co. The BTM/UBSW index measures sales growth with the year 1977 equaling 100.

The Redbook Retail Sales Average is a sales-weighted average of annual growth in same-store sales at discount, department and chain stores that report their results on a weekly basis. The average is compiled from a sample of general merchandise retailers representing about 9,000 stores. Same store sales measure revenues at stores open at least a year.

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

Reuters and the Associated Press contributed to this report.