Microsoft's Bing and other Internet search services overtook Yahoo! for the first time to become the number two search engine in the United States in August, The Nielsen Co. said Tuesday.
Microsoft's Bing, MSN and Windows Live had a 13.9 percent share of US search volume in August, up 0.25 percent from July, while Yahoo! had a 13.1 percent share of US Internet searches, down from 14.6 percent in July, Nielsen said.
Google continued to dominate the lucrative search and advertising market with a 65.1 percent of all Internet searches in August, Nielsen said.
Year-over-year, Microsoft sites have increased their search share from 10.7 percent in August 2009 to 13.9 percent in August 2010 while Yahoo! has fallen from 16.0 percent a year ago to its current 13.1 percent, Nielsen said.
Google held steady at 65 percent.
IAC's Ask.com had a 2.1 percent share of Internet searches in August, according to Nielsen, while AOL had a 2.0 percent share.
ComScore has not yet released its search figures for August but the online tracking firm reported last month that Google had a 65.8 percent share of the US search market in July followed by Yahoo! with 17.1 percent and Microsoft sites with 11.0 percent.
Yahoo! and Microsoft forged a Web search and advertising partnership a year ago that set the stage for a joint offensive against Google.
Under the agreement, Yahoo! will use Microsoft's search engine on its own sites while providing the exclusive global sales force for premium advertisers.
Microsoft last month began handling all Yahoo! online searches in Canada and the United States and will eventually power Internet searches at Yahoo! websites worldwide.
Explore further: Lions Gate partners with online outfit RocketJump