Nielsen shared some new search market findings, indicating that Bing has overtaken Yahoo as the number two search engine in the U.S. for the first time. That’s MSN/Windows Live/Bing, to be more precise, which holds 13.9% of the market (as of August), according to the firm.

Yahoo holds a 13.1% share, a decline from 14.6% in July. Google saw little change, but accounted for 65% of all U.S. searches. 

The numbers do not take into account the Search Alliance between Microsoft and Yahoo, as Bing started officially powering Yahoo searches on August 24. Nielsen says, "If we combined Bing-powered search in August pro-forma, it would represent a 26% share of search."

"In terms of a year-over-year comparison, Google has seen little change in its share of search while Yahoo! has seen a small but steady decline, going from a 16.0% share to 13.1% (a delta drop of 2.9% or a relative drop of 18%)," the firm says. "MSN/Windows Live/Bing’s share has grown from 10.7% in August 2009 to 13.9% (a delta increase of 3.2% or a relative increase of 30%)."

Clearly, good things are happening for Bing, and with the Search Alliance firmly in place in the U.S. and Canada, with the international transition on the way, Bing’s numbers will be doing quite well going forward. Of course they still have a search partnership with Facebook and Windows Phone 7 sales to look forward to as well.