U.S. chain store retail sales rose for the second consecutive week, as Mother's Day sales helped get May off to a positive start, a retail report said on Tuesday.

Sales rose 0.7 percent in the week ended May 7, compared with a 0.5 percent increase the previous week, the International Council of Shopping Centers (search) and UBS said in a joint report.

Compared with the same week a year ago, sales momentum improved to a 3.5 percent increase after a 3.0 percent rise the preceding week.

"The first week of May began on a positive note as we saw retail chain store sales rise as Mother's Day provided the consumer with a need to shop and to spend," said Michael Niemira, ICSC's chief economist and director of research.

"Spending was uneven across the country, however, the Northeast and the Midwest posted the best gains while the weakest demand was in the South and West. For May, we expect sales to rise by 3.0 percent to 3.5 percent on a comp-store basis," Niemira added.

The ICSC-UBS Weekly Chain Store Sales Snapshot is compiled from a group of major discount, department and chain stores across the country that report their weekly results.