Retail sales at discount, chain and department stores fell sharply in the first three weeks of December, suggesting deep discounts failed to lure wary consumers to stores, Instinet Research said in its weekly report on Wednesday. 

The Redbook Retail Sales Average dropped 4.5 percent in the three weeks ended Dec. 22 compared to the same period last month. 

Year-over-year sales in the same period fell 0.6 percent compared with a 1.1 percent drop in the previous week. 

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.