Google's U.S. search share up, Yahoo and Microsoft down

Google continued to increase its share of the U.S. search market in February, widening the gap that Microsoft hopes to fill by buying Yahoo.

In February, Google's share of core searches by U.S. Internet users rose to 59.2 percent, up from 58.5 percent in January, according to figures from market research company comScore.

During the same period, Yahoo's share slipped to 21.6 percent, from 22.2 percent a month earlier, while Microsoft's share slipped to 9.6 percent from 9.8 percent. AOL is clinging to a 4.9 percent share, while Ask saw its share rise slightly to 4.6 percent from 4.5 percent in January; comScore excludes mapping, local directory, and video sharing sites off the core domain from its search.

Worldwide, the No. 3 search engine is China's Baidu.com, behind Google and Yahoo but ahead of Microsoft's MSN-Windows Live properties, according to comScore.

Microsoft's $44.6 billion offer for Yahoo is not just about bolstering its share of the search market: Microsoft wants to strengthen its position against Google in a broader range of online services, including advertising, not all of which is search-based.

The reach of the companies' advertising networks is far broader than the audience for their home pages. In February, 90 percent of U.S. Internet users saw a page served by advertising network Platform A, and 88 percent a page from advertising.com, both of which are operated by AOL, even though only 49 percent of surfers visited an AOL.com page, according to comScore.

Likewise, pages from Yahoo's advertising network were seen by 85 percent of U.S. surfers in February, while only 51 percent visited the Yahoo.com home page. Google's advertising network snared 79 percent of U.S. surfers, while Google's site was visited by 69 percent. Only 31 percent visited the MSN.com home page, with 56 percent visiting MSN or other Windows Live services, comScore said.