LONDON – Carat, Europe's biggest media buyer, has trimmed its growth forecasts for global spending on advertising for this year and next after revising its estimates for the United States, Britain, Spain and China.

Carat, which belongs to British marketing group Aegis Group , said on Wednesday it now expected 4.9 percent growth instead of 6 percent for 2008 and 4.8 percent for 2009, down from a previous estimate of 4.9 percent.

“It's clear that the worldwide economic issues affecting businesses are having an impact on where and how advertisers spend their money,” said Jerry Buhlmann, chief executive of Aegis Media, a part of Aegis Group.

“It is also significant that the U.S. and the UK, as the highest spenders on advertising in their regions, are showing reductions in our forecasts,” he added in a statement.

Carat still forecast higher advertising spend in almost all regions, with double-digit growth in Eastern Europe, Asia and Latin America.

But it forecast a drop of 2.3 percent instead of an increase of 3.8 percent this year for Spain, which has been hit by a severe housing downturn.

Carat predicted that the Internet would overtake radio this year to become the world's third-most popular medium behind television and print, thanks to its ability to target and track consumers by throwing up advertising among Web search results.

Globally, all sectors apart from newspapers are forecast by Carat to grow this year and next, partly due to the U.S. presidential elections and the Olympics, which will boost TV ad spend, although a post-Olympics lull is seen in China.

(Reporting by Georgina Prodhan; Editing by David Cowell)