Shopping declined by 0.1 percent on the week but gained 0.5 percent from a year ago, the report said.

"Despite the Mother's Day weekend approaching, consumers were cautious in their spending," the report said.

The retail group noted that temperatures for the week were slightly warmer than normal but colder than a year ago -- the third consecutive week of disappointing weather for retailers, the report noted.

High gas prices also crimped spending, the national average price of unleaded jumping 11 cents per gallon to an average $3.722 on May 12.