U.S. chain store sales rose in the first week of January, as larger than average purchases were the reason for this weeks growth, a report said on Tuesday.

Sales at major retailers rose by 3.1 percent on a year-over-year basis for the week ended Jan. 8, while sales in January to-date were up 1.1 percent compared with December said Redbook Research (search), an independent company.

"This may have been partly due to the seasonal mix shifting to bigger ticket items such as coats and electronics, but may also reflect gift-card redemptions and bargain hunting by shoppers trained to defer expensive purchases to post holiday sales," the report said.

The Redbook data are compiled from a sample of same-store sales (search) at general merchandise retailers representing about 9,000 stores. Same-store sales measure revenue at stores open at least one year.