Research outfit comScore has released the US search engine rankings for October 2009. During the month, Americans conducted some 14.3 billion core searches, the majority of which (9.4 billion) were through Google, which held 65.4% of the search market, up from 64.9% in September. Yahoo served some 2.6 billion searches, trailed by Microsoft with 1.4 billion, Ask with 552 million, and AOL with 412 million.

It was a rough month for Google's closest competitor, Yahoo, which accounted for some 18% of the search market share, a 0.8% loss from the month prior. Microsoft sites grew 0.5%, making up 9.9% of the search market -- a noteworthy increase, though Redmond is surely bummed about not chipping any figures away from Google's presence. Meanwhile, Ask remained flat at 3.9%, and AOL lost 0.1%, settling with 2.9% of the market.