NEW YORK (AP) – The nation’s retailers had a strong start to the holiday shopping season, according to results announced Saturday by a national research group that tracks sales at mall-based stores. One big exception was Wal-Mart Stores Inc., which said it expects to report same-store sales in November below its already lackluster forecast.

According to ShopperTrak RCT Corp., which tracks total sales at more than 45,000 mall-based retail outlets, total sales rose 6 percent to $8.96 billion on Friday, the start of the holiday shopping season, compared to the same day a year ago.

“Although we anticipated a solid consumer turnout for Black Friday, this data shows an even larger increase than expected as consumers proved they were willing to spend,” said Bill Martin, co-founder of ShopperTrak, in a statement.

Wal-Mart, however, estimated it will post a 0.1 percent decline in same-store sales, or sales at stores opened at least a year, in November. That’s slightly below its original projections for flat sales for the month, compared to the year-ago period. The results cover the four-week period that ended through Friday. Same-store sales are considered a key indicator of a retailer’s health.

J.C. Penney Co. said in a separate statement released Saturday that the holiday shopping season was “off to a good start.”

“We have seen brisk traffic in our stores, and our ‘redbox gifts’ selection is being well-received by customers,” Penney said, referring to its holiday must-have items. It said that home entertainment, fashion jewelry, children’s apparel, housewares, holiday decorations and women’s shoes were among the most popular items Friday.

Wal-Mart and other major retailers are expected to report final same-store results for November on Thursday.

Wal-Mart’s disappointing performance in November is the latest in a string of anemic sales gains for the discount store, which is struggling to expand its appeal to higher-income shoppers. According to the International Council of Shopping Centers, Wal-Mart has averaged a meager 2.4 percent gain in same-store sales for the February-October period. That compares with a same-store sales 4.8 percent gain for discount rival Target Corp. Penney has averaged a 4.5 percent gain in same-store sales for the February-October period.

Wal-Mart, which had downplayed its emphasis on discounting, or what it calls rollbacks, stepped up its campaign in mid-October, with price reductions on over 100 toys. The move was followed by price cuts on consumer electronics and small appliances earlier this month.

While Black Friday – so named because it was traditionally when the surge of shopping made stores profitable – starts holiday shopping, it is not considered a bellwether for the season. However, merchants see Black Friday as setting an important tone to the overall season: what consumers see that day influences where they will shop for the rest of the year.