Combined, Microsoft and Yahoo captured 28.5% of total U.S. searches in August, while Google slipped 0.4% to a still dominant 65.4%.
Google remained in the vanguard of U.S. search engine rankings in August with 65.4% of total searches, although the company's dominance showed an almost imperceptible decline of 0.4% from July's 65.8% market share. Google recorded 66.2% of searches in June.
Released late Thursday by comScore, the rankings show that the combination of Microsoft and Yahoo -- the so-called Microhoo partnership -- totaled 28.5%. The two firms have cooperated on search after Microsoft's attempt to acquire Yahoo failed a few years ago.
Companies providing search technology have tried to put their best foot forward by attempting to include some peripheral search technology in their rankings. comScore includes Google News and its YouTube unit in its rankings, but its mapping searches can be excluded from some rankings.
"Americans conducted more than 16.9 billion total core search queries in August with Google sites leading with 10.3 billion searches," according to the comScore report. The market research firm, which measures the digital world, said Yahoo sites recorded 3.6 billion total core search queries and Microsoft sites had 2.2 billion.
comScore defined "total core search" as searches based on the five major search engines including their partner searches, cross-channel searches and contextual searches. The fourth and fifth ranked search engines -- Ask Network and AOL Network, respectively -- retained their identical rankings in July and August. Ask had 3.8% of total searches and AOL had 2.3%.
Different market measuring firms do not always coordinate perfectly with each other in search rankings. For instance, Nielsen recently said Google had 65% of the market while Microsoft's Bing had 13.9%. Yahoo had 13.1 %.