Online auctions sites are increasingly popular with online shoppers according to figures from APACS.

The UK payments association representing card companies, has released its 2005 e-commerce figures, which reveal that 14 per cent of the 34 million adults who use the internet (4.9 million) made their most recent purchase from an auction site last year.

Sales at sites, such as eBay and Amazon marketplace accounted for 79 million transactions over this period, and £2.8 billion was spent.

Looking at the wider e-commerce market, for the first time nearly seven out of 10 adult internet users paid for something online purchase during last year.

In addition to the increase in the number of adults spending online, the number of purchases being made is growing - the average number of purchases made by online shoppers in the year rose from 13.6 in 2004 to 18.5 in 2005.

With safety message getting across about the benefits of using a credit card as opposed to cheque or cash transactions, credit cards are used for nearly half of all online payments. On the high street, only six per cent of payments are made using credit cards.

This was reflected in total online card spending figures, which were up from 262 million transactions in 2004 to 310 million in 2005. The value of these transactions increased from £16 billion in 2004 to £22 billion last year.

Sandra Quinn, director of communications at APACS, said:

"The internet is now very much part of mainstream culture in the UK, and for many people it is the first port of call when looking for certain items to buy.

!In 2005, for the first time, more than half of all adults made an online pu rchase, which demonstrates this increasingly important role the Internet is playing in the lives of UK consumers.

However she warned that consumers must be alert to the threats posed by internet criminals, and should take steps to protect themselves when shopping online.

"Consumers should only ever buy online from a computer with up-to-date virus protection, and only shop at secure websites. We all need to be vigilant and be careful with our cards and personal details."

APACS said consumers should visit websites such as CardWatch , Bank Safe Online , Get Safe Online or the Home Office identity theft help website for hints and tips about how to stay safe online.