WASHINGTON -- The key year-end U.S. holiday shopping season is off to a strong start in stores and online, according to surveys and other data Monday.

The National Retail Federation said its survey showed 75.6 percent of consumers were out shopping on "Black Friday" weekend.

Wal-Mart, the giant U.S. retailer, said its U.S. stores sold a record $1.43 billion worth of merchandise in the Friday kickoff, AFP reported.

"Shoppers did not waste any time this weekend looking for great deals in the wee hours of the morning," said NRF President Tracy Mullin.

The retail figures for the holiday period could provide a boost to the uneven us economic recovery, amid lingering fears that consumers may rein in spending because of a cautious outlook and a potential war with Iraq.

Consumer spending accounts for about two-thirds of U.S. economic activity, and the year-end season often accounts for about half of the profits of some retailers, AFP reported. The term "Black Friday" was coined as the time at which some retailers moved from the loss column, or the "red" and into profit, or "black."

Still analysts were not overly optimistic about the sales picture, which is expected to show growth of about three to five percent.

"The biggest challenge for retailers is still next weekend," said Britt Beemer, analyst with America's Research Group. "If people take next weekend off, retailers are going to be singing the blues after Christmas."

In the virtual world, sales were also seen as strong.

A Comscore Media Metrix study found that online sales on the day after thanksgiving, widely referred to U.S. as "Black Friday" and traditionally the busiest shopping day of the year, jumped 30 percent from a year ago to $195.6 million.

"The largest growth drive of online holiday sales is the sheer volume of online buyers, up more than 30 percent in recent weeks," Media Metrix said.

Computer hardware, consumer electronics and apparel were the top three categories for non-travel sales online, the research firm said.

Online shopping sales by America online subscribers rose 26 percent year-over-year during the U.S. thanksgiving holiday shopping week November 25 to December 1, the company said.

Online retail leader amazon.com expects sales in the traditionally lucrative holiday season to be strong despite the late start to the holiday season and troubling economic environment.

"(Despite) the shortened holiday season and difficult economy, we are expecting our busiest holiday season ever," company spokeswoman Ling Hong said. "We are still sticking with (our fourth quarter sales guidance)."

In October, the Internet retailer forecast sales will rise 19-28 percent to 1.3 to $1.4 billion from the same period a year earlier.