Yahoo chief Carol Bartz sees trouble for Google

Carol Bartz said that Google would have to "do a lot more than search" and suggested that it would have to "grow a company the size of Yahoo every year".

Ms Bartz made the comments when asked if Yahoo's sprawling network of sites and services had a defined brand image.

Yahoo is one of the largest sites in the world with an audience of more than 200m, according to analysts Nielsen.

It competes with Google in the search market, but has only 17% of the US market, compared to Google's 65%, according to Comscore. Yahoo recently did a deal to use Microsoft's Bing to power searches on its sites.

"Google is going to have a problem because Google is only known for search," said Ms Bartz.

"It is only half our business; it's 99.9% of their business. They've got to find other things to do.

"Google has to grow a company the size of Yahoo every year to be interesting."

Yahoo has more than 70 websites and services, many of which are available in 20 languages around the world.