NEW YORK (CNN/Money) - Uncertain about the strength of Friday's official holiday shopping season kickoff, Wal-Mart Stores Inc. and Federated Department Stores Monday reiterated expectations for sluggish November sales.

Wal-Mart (WMT: down $0.45 to $53.31, Research, Estimates), the world's largest retailer, said it continues to expect November sales at stores open at least a year, a key gauge known as same-store sales, at the low end of its forecast for a 2-to-4 percent increase. The Bentonville, Ark.-based chain said a calendar shift that pushes Thanksgiving later this year makes year-over-year comparisons difficult to predict.

Wal-Mart shares finished down 19 cents at $53.76 Friday.

Meanwhile, Federated, (FD: down $0.76 to $31.60, Research, Estimates) parent of Macy's and Bloomingdale's, said it continues to expect November same-store sales that are flat to down 2.5 percent for the November/December period. However, the Cincinnati-based retailer said it could not provide accurate guidance on November sales, which continue to be disappointing.

Federated's shares shed 43 cents to finish Friday's session at $32.36.

Retailers are concerned that a difficult economy and worries about a potential war with Iraq could dampen sales during the holiday shopping season, when merchants typically make up to half their annual profits and sales. However, the industry as a whole remains cautiously optimistic as they offer big discounts early to help entice consumers.