Online sales growth in the U.S. slowed last week to 20 percent as U.S. retailers lowered prices to lure shoppers during what may be the worst holiday shopping season in five years.

Internet retail purchases rose to $4.58 billion in the week through Dec. 7, Virginia-based ComScore Inc. said Sunday in a statement. Online sales of video games and consoles more than doubled, representing the strongest growing product category, ComScore said.

Online spending, which accounts for more than 3 percent of all retail sales, may increase 20 percent to $29.5 billion in November and December, ComScore estimated. That trails the 26 percent growth in online sales during the holidays in 2006 as consumers seek less-expensive items this year.

"There really wasn't any big hot product that came out pre-holiday season to be sold as a holiday gift," said Larry Freed, chief executive officer of ForeSee Results, an online research firm in Ann Arbor, Mich. "There really hasn't been the hot product, which also creates a furor to get on the Web site to buy it before it comes out."

Online sales in the 37 days since Nov. 1 have gained 18 percent to $18 billion, ComScore said. A year ago, ComScore reported a 25 percent increase in the first 38 days of the holiday shopping season.

Online sales continue to grow faster than retailers' total sales. The National Retail Federation predicts that November and December sales will rise 4 percent, the smallest gain since 2002.