Behavioral marketing and adware firm Claria has begun to test a personalized search service that tailors search results to web surfers' behavior, reports CNET. Claria's software tracks users' movements around the web and is installed on tens of millions of desktops. By analyzing those users' search behavior, Claria will now be able to offer search results that are more relevant to each user.

The move comes a day after Microsoft called off acquisition talks with Claria. Just this week, Microsoft's Steve Ballmer emphasized the importance of search for the software giant.

Claria's announcement may reflect its intent to highlight Microsoft's lost opportunity to compete with personalized-search rivals, such as Google, which introduced a similar offering two weeks ago. Other major search players, including Yahoo, Ask Jeeves, and Amazon's A9.com are said to also be working on personalized search initiatives.

Claria's search engine is now available to only a small group of testers within its network, but Claria said it would be launched by the end of this year.