RESTON, VA: Bing stole market share from main rival Google in January, as competition in the US search market increases.

Latest figures from comScore suggest Microsoft's search sites, including Bing, captured 13.1% of explicit core searches last month, up 1.1% from December 2010, while Yahoo was up 0.1% on 16.1%.

Despite its overall share declining 1% month-on-month, Google remains dominant with 65.6% of the explicit core search market.

On the broader total core search metric - which includes partner searches, cross-channel and contextual searches - Google was up 0.3% to 64.6%, while Yahoo was down from 18.8% to 17.9%

But Bing, which has been heavily-promoted since its 2009 launch, registered the highest total core search growth for the month, and was up 0.8% to 12.8%.

The Ask Network and AOL were the fourth- and fifth-largest search networks respectively.

In all, US web users made 18.56bn searches in January, up 2% on December.

Earlier this month, Bing announced that it is personalising search results based on data such as the user's search history and location.

This technique is already employed by Google.

In a blog post on the topic, Microsoft said: "The beauty of thinking differently about personalized searching is that it enables us to construct elegant solutions that require a minimal amount of personal information and, frankly, often exhibit better results than a more computationally complex predictive model alone."

Thanks to a deal struck by Microsoft and Yahoo which went into effect in August 2010, Bing now powers Yahoo search results in the US and Canada.

Data sourced from comScore/Microsoft; additional content by Warc staff