Online advertising will more than double this year as the number of people with internet access continues to increase, according to research by the media agency Optimedia.

The research suggests advertisers will spend £210m online this year - more than twice the £100m spent in 2000.

It strongly contradicts the more pessimistic estimates being issued by rival forecasters.

Optimedia says the rise will come mainly from traditional advertisers turning to the web for the first time.

"Lots of people are predicting a crisis in internet advertising, but we think that's based on the collapse of the dot.coms - and they are by no means the biggest online advertisers," said Optimedia marketing director Sandra Collins.

"We're seeing year-on-year growth of 300% from our clients and many of our traditional clients such as L'Oreal and MFI are only just starting to dip their toes in the water.

"I think we can expect a lot of growth to come from them."

Optimedia predicts internet adspend will rise to £710m by 2005.

The company says this will be driven by improvements in the quality of internet adverts and a rapid growth in the number of people who use the internet regularly.

Optimedia forecasts internet penetration in the UK will rise from 13.9m web users at the end of last year to 20m by the end of 2001 and 32.5m by the end of 2005.

And, according to the research, more people will access the internet via their TV sets.

TV is expected to become almost as popular as computers for accessing the web.

Even the expected economic downturn is unlikely to leave a serious dent in advertising growth rates, according to Optimedia.

Internet advertising allows companies to track exactly how many people have clicked on to their adverts.

Optimedia believes this accountability will make the web more attractive than traditional media when advertising budgets are squeezed.