US online retail sales on Cyber Monday hit an all-time high and surpassed $1 billion for the first time for any single day of web shopping, according to analytics firm comScore.

Shoppers spent $1.028 billion online on Monday, 16 percent more than last year, comScore reported on Wednesday.  Average spending per transaction rose 10 percent to $60.05, while the total number of transactions was up 6 percent to 17.1 million.   

For the holiday season so far, online retail sales have hit $13.55 billion, up 13 percent from 2009, according to comScore.   

ComScore expects online retail sales to rise 11 percent for the 2010 holiday season. It has raised its closely watched forecast twice.   

The Monday after the US Thanksgiving holiday was dubbed Cyber Monday five years ago to entice shoppers online.Originally, people returning to work after the break browsed for gifts on office computers, but the day has since attracted a wider group of shoppers.

Online spending growth is outpacing that at brick-and-mortar stores, where sales gains are more modest. But e-commerce still makes up just a small percentage of the overall retail market. - Reuters