U.S. retail sales at discount, chain and department stores rose in the first two retail weeks of February, boosted by Valentine's Day promotions, Instinet Research said in its weekly report on Wednesday. 

The Redbook Retail Sales Average rose 0.8 percent in the two weeks ended Feb. 16 compared with the same period last month. 

Year-over-year sales in the week ended Feb. 16 rose 3.9 percent, while month-to-date sales compared to February 2001 grew 4.0 percent. 

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.