Preliminary results show that retailers had a less than stellar holiday season and seasonal growth figures are likely to come in under initial expectations. The International Council of Shopping Centers reported that sales at U.S. chain stores increased by 2.8 percent over last year in the last week in December, a highly anticipated indicator because shoppers return to the malls to cash in their holiday gift cards and take advantage of post-holiday sales. “For December, we continue to expect sales to increase by about 2.5 percent,” said Michael Niemira, ICSC’s chief economist. The ICSC had earlier lowered its holiday sales forecast to 2.5 percent from an initial projection of 3 percent same-store sales growth.