Microsoft's Bing search engine, which made its high-profile debut this summer, occupied some 10.7 percent of the U.S. search engine market in August, according to new data released by research firm Nielsen.

That market share made Bing the fastest-growing online search provider, with a month-over-month increase of 22.1 percent. It came in third place in the rankings, behind Yahoo and Google.

By contrast, Yahoo saw its month-over-month share of the market decrease by 4.2 percent, to a flat 16 percent. Market leader Google saw growth of 2.6 percent during the same period, and held 64.6 percent of overall searches.

Following up in distant fourth and fifth place were AOL Search and Ask.com search, with 3.1 percent and 1.7 percent of the market, respectively.

On July 29, Microsoft and Yahoo announced a search-advertising partnership deal that will see Bing become the search engine on Yahoo's sites, meaning that Bing’s share of the market could potentially expand to nearly 30 percent—a combination of Microsoft’s and Yahoo’s current market share—when the deal is finally actualized in early 2010.

That would theoretically put Microsoft in a stronger competitive position against Google and its 64.6 percent, although some analysts have asserted that even the agreement between Google's two archrivals is a long way from being a genuine survival threat.

In announcing the original deal, Microsoft CEO Steve Ballmer suggested that the partnership would feed exponentially more actionable data into Bing’s back-office operations and thus allow it to produce more relevant results for end users.

Since its June 3 launch, Bing has made incremental gains in the search market, buoyed by a massive Microsoft ad campaign estimated at between $80 million and $100 million. Those gains led Ballmer to exclaim at Microsoft’s Worldwide Partner Conference in July that the search engine had momentum.

"Man, oh man, have we taken a lot of abuse, and we’re still just an itsy-bitsy part of the market, but we have a little bit of mojo," he told the audience at the event.

In July, research firm ComScore reported that Bing’s share of the U.S. search engine market had increased to 8.9 percent from 8.4 percent in June, while Google’s own share stood at 64.7 percent, a drop of 0.3 percent. That same study showed Yahoo’s market share fall slightly to 19.3 percent.