Retailers are hoping last week's strong start to the holiday shopping season at U.S. malls and stores translates into a busy buying season online, which officially begins Monday.

The Monday after the American Thanksgiving, tagged "Cyber Monday" by the U.S. National Retail Federation, marks the first big online shopping surge for many merchants as consumers return to their work computers.

A number of retailers are hosting one-day sales or special offers for the occasion. Internet research firm comScore Inc. estimated online sales may exceed $700 million US online on Monday.

As for brick-and-mortar outlets, ShopperTrak RCT Corp., which tracks total sales at more than 50,000 retail outlets, reported late Sunday that sales on Friday and Saturday combined rose 7.2 per cent to $16.4 billion US from the same two-day period a year ago.

The biggest draw was electronics, benefitting chains like Best Buy Co. and discounters such as Wal-Mart Stores Inc. and Target Corp. Popular-priced department stores including J.C. Penney Co. and Kohl's Corp. drew in crowds with good deals.

Toy stores like Toys "R" Us Inc. fared well too. Still, apparel sales appeared to be mixed at mall-based clothing stores, though a cold weather snap helped spur sales of outerwear and other winter-related items.

"This was a really good start," said Bill Martin, cofounder of ShopperTrak. "There seemed to be a lot of pent-up demand."

Now the attention moves online. Toys "R" Us Inc. will hold a one-day online sale and rival eToys.com will launch a two-day sale. Wal-Mart Stores Inc. will begin five days of online-only sales.

Online jeweller Blue Nile Inc. will give customers 20 per cent off purchases paid through PayPal, eBay Inc.'s electronic payment division. Target Corp., Circuit City Stores Inc., Sears Holdings Corp., Crate & Barrel, the Discovery Store and Overstock.com Inc. are among dozens of retailers offering free shipping that day.

"The online community is getting more competitive as the amount of new customers slows," according to Scott Silverman, executive director of Shop.org, an online arm of the National Retail Federation.

"Add to that the concerns about the economy, and promotions and sales provide a great way to get people excited."

Silverman said the number of retailers offering free shipping with no conditions, such as a minimum purchase, has jumped to 41.4 per cent from 36 per cent in 2006.

Nearly one-third of retailers are also having special one-day sales for Cyber Monday. Forty-two per cent plan some kind of promotion, according to the NRF's annual survey.

In fact, the number of retailers hosting online deals on the Monday after Thanksgiving has surged to 72 per cent of those polled from 42 per cent just two years ago.