U.S. retail sales were up a touch in the week ending Saturday with increased traffic at shopping malls, a trade group said. The International Council of Shopping Centers said sales rose 0.5 percent compared to the previous week and 4.5 percent compared to the same week of 2011. Traffic increased in shopping malls, but there was a trade-off. Customer traffic for the week declined at factory outlet centers, the trade group said. Unseasonably warm weather continued to shape the retail environment, but gasoline prices bucked a recent trend and turned lower for the week, \"their first sequential weekly decline since the week of Jan. 23,\" the trade group said. The ICSC said the average national price decline was \"encouraging but slight,\" with prices down by 0.2 cent to $3.939 per gallon. With the drop so slight, the average price of gasoline remained 71 cents higher than it was in late December, the U.S. Energy Information Administration said.