US online advertising revenue grew 26 per cent to a record $5.8bn in the first six months of the year, according to a new study.

The study by Interactive Advertising Bureau (IAB) and PricewaterhouseCoopers also found that Internet advertising revenue totaled $3bn for the second quarter of 2005, an increase of 26 per cent compared with the same period a year ago.

Spending on paid search listings rose 27 per cent to $2.3bn for the first six months of 2005, the report said. Paid search listings allow advertisers to pay to display advertisements next to relevant search terms.

Overall, paid search listings account for 40 per cent of all online advertising sales, regular display ads, such as Web page banners, represent 20 per cent, classified advertisements grew to 18 per cent, while rich media (video and audio) comprises 8 per cent.

"It is clear from this continued growth, that most agencies and marketers are now committed to Interactive as a critical medium in reaching their audiences, as well as engaging them in more immersive brand experiences," said Greg Stuart, president and chief executive of the IAB.

"At the end of the day, it is about increased effectiveness from your marketing dollars and Interactive delivers this."

David Silverman, Partner, PricewaterhouseCoopers, added: "The consistent growth in overall revenues shows marketers may be shifting more of their total advertising budgets to online. This is a natural development as research shows more consumers are spending a larger percentage of their media time online, while the flow of advertising dollars follows."