U.S. chain store sales (search) made slight gains in the last week of August, but less mortgage refinancing activity compared with last year, a lack of tax rebate checks and higher gasoline prices left less money in shoppers' pockets, a report said on Tuesday.

Sales at major retailers increased by 1.3 percent on a year-over-year basis for the week ended Aug. 28, slightly up from the preceding week's 1.0 percent pace, said Redbook Research (search), an independent company. Sales in August so far were down 1.1 percent compared with July.

"Most retailers are facing tough comparisons with strong year-ago performance numbers in part due to rising gasoline prices, lack of child tax rebate checks and less mortgage refinancing activity squeezing consumer spending budgets," the report said.

Redbook's preliminary outlook for September was for annual same-store sales growth of 2.8 percent.

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.