Though Google is still king of the U.S. search engine market, the company saw its share drop slightly in January, while Bing continued to pick up more steam, according to ComScore.

For the first month of 2011, the market researcher said Friday, Google's share of all searches dropped by 1 percentage point to 65.6 percent. At the same time, Bing's share crept up by 1.1 point to reach 13.1 percent. That left Yahoo pretty much flat with a 16.1 percent cut of all searches for January.

Those numbers follow a pattern that's marked the past several months in which Google sheds a smidge of share, while Bing edges up a bit more. However, the changes have generally been measured in fractions of a percentage point rather than the full point seen in January.

Looking at the hard numbers, the total number of core searches rose from 16.4 billion in December to 16.9 billion in January--a 3 percent increase. Google was No. 1, accounting for 11.1 billion of those searches in January. Yahoo took second place with 2.7 billion, while Bing took third place with 2.2 billion. The total core searches here reflected 1 percent increase for Google over December, a 4 percent jump for Yahoo, and a 13 percent increase for Bing.

Per usual, ComScore's figures look specifically at explicit core searches, meaning search terms manually entered on a Web page. The data also takes into account all of a company's search sites. So in the case of Google, the results cover searches on its main page as well as those at YouTube, Google News, Google Images, and other properties.

Beyond examining core searches, ComScore also tracked "powered by" searches. For January, Google's share of "powered by" searches at its own sites as well at on AOL and on Ask.com was 68.2 percent, while Bing searches on Microsoft and Yahoo sites hit 25.6 percent. Here too, January continued a familiar pattern of Google losing a small percentage of its "powered by" share and Bing winning a little bit more.

Another recent report echos ComScore's findings for January. Data released last week by Experian Hitwise showed a dip in searches at Google and a rise for Bing.