Internet advertising in the UK continues to boost media spend, as search engine ads appear to outstrip their display counterparts.

A new report by researcher Thomson Intermedia and accountants KMPG says overall adspend in the UK grew by 5.4% in 2005, pushed on by expansion of internet revenues.

Although the report does not give specific search-based advertising figures, Thomson's head of insight Paul Ryan comments: "A significant part of online ad spending is unknowable and that's becoming such a major part of online advertising."

He adds: "We base our view on market sentiment and what several hundred of our major clients are telling us. Anecdotally we believe that type of advertising is taking a larger and larger part of adspend in new media."

And TI ceo Sarah Jane Thompson opines: "In the longer term we are very conscious that as this medium continues its explosive growth, there is a lack of marketing spend transparency."

Three sectors dominate online adspend, with entertainment, media and leisure accounting for 26% of the total, IT and communications companies 20% and financial companies 19%.

Data sourced from Brand Republic (UK); additional content by WARC staff