U.S. chain store sales (search) slowed somewhat in the latest week, dragged down by weak department store results, though cooler weather spurred sales of autumn clothing, Instinet Research said in its Redbook report (search) Tuesday.

Sales at major retailers rose 3.1 percent in the week ended Oct. 4 compared with the same week a year ago, after rising 3.2 percent in the preceding week, the report said.

Sales fell 1.3 percent in September compared with August, the report said.

Sluggish department store sales tamed overall retail sales, although clothiers reported a pick up in fall apparel, owing to cooler weather, especially in the Great Lakes region (search) of the United States.

The Redbook data are compiled from a sample of same-store sales at general merchandise retailers representing about 9,000 stores. Same-store sales measure revenue at stores open at least one year. The index is released weekly by Instinet Research, a division of Instinet, a Reuters-owned electronic brokerage.