Yahoo! increased its share of the US search market by nearly a percentage point in April and Microsoft's new search engine Bing also recorded a slight gain, online tracking firm comScore said Tuesday.
Yahoo!, Microsoft's search partner, saw its share of the lucrative US search and advertising market increase to 17.7 percent in April from 16.9 percent in March, the Web analytics firm said.
Bing's share of the US search market rose to 11.8 percent in April from 11.7 percent in March -- the 11th straight month of modest gains for Microsoft's new search engine.
Google remained the overwhelming leader of the US search market in April although its market share slipped to 64.4 percent from 65.1 percent in March.
Ask.com's share fell to 3.7 percent in April from 3.8 percent in March while AOL's dropped to 2.4 percent in April from 2.5 percent in March.
Technology and financial aanalysts said the April figures had been affected somewhat in Yahoo!'s favor by a new feature in Yahoo! News which counts each view of a photo slideshow as a search query.
ComScore said the new Yahoo! feature meets its "established criteria for counting search queries."
ComScore said Americans conducted a total of 15.5 billion searches in April, up one percent from March.
It said Google sites accounted for 10 billion searches, followed by Yahoo! (2.8 billion), Microsoft (1.8 billion), Ask Network (574 million) and AOL (371 million).
April was the 11th consecutive month of slight gains in search share for Bing, which Microsoft unveiled in June accompanied by a 100-million-dollar advertising campaign in a bid to challenge search juggernaut Google.
Yahoo! and Microsoft unveiled a 10-year Web search and advertising partnership in July 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.
Explore further: Japan court orders Facebook to reveal revenge porn IP addresses