Sales at U.S. outlets open at least a year gained 6 percent, and international same-store sales advanced 21 percent.

Costco has outpaced Sam's Club and BJ's Wholesale Club Inc., other warehouse merchants that charge an annual membership fee, by offering luxury goods such as a $170 Waterford crystal menorah. Costco also sells its own Kirkland brand of items ranging from outdoor gas grill-ovens to diapers.

U.S. retailers, led by Wal-Mart Stores Inc., have cut prices to lure consumers beset by higher food and energy costs. The National Retail Federation forecast the smallest holiday sales gain in five years.

Most U.S. retailers reported November sales today. Sam's Club, the warehouse division of Wal-Mart, said November same-store sales in the U.S. rose 7.1 percent, including fuel. Costco's sales figures also include fuel.

Warehouse club chains have had "above-average trends for retail over the past few months," as consumers cope with the housing slump, said Jon Fisher, who helps manage $22 billion, including retailers' shares, at Fifth Third Asset Management in Minneapolis.

Costco's November same-store sales topped the analyst estimate for a gain of 6.1 percent, according to Retail Metrics, a research firm in Swampscott, Mass.