Microsoft CEO Steve Ballmer has described the Bing search engine as 'growing like a weed', as it battled market giant Google.

Ballmer told USA Today that the success of Kinect and Xbox has given renewed confidence in the company backing its own decisions.

"We've made bold technology bets," said Ballmer. "We've bet on the Cloud and our Enterprise business; it's going fantastic.

Bets

"We made the bet on Xbox; we made the bet on Kinect," he added. "We bet on Bing and are growing like a weed in that business. So I feel pretty good about the bets."

Bing has been gamely battling Google - but despite US growth in December is not making much of an impact on Google's dominance.

According to ComScore's latest US figures last week, Bing put on a 4 per cent growth, but Google a 3 per cent growth in the same period.