Google accounted for 68.29 percent of all U.S. searches in the four weeks ending May 31, Hitwise reported Wednesday. 

Yahoo, MSN and Ask.com were used in 19.95, 5.89 and 4.23 percent of U.S. searches, respectively. The remaining 41 search engines in the Hitwise Search Engine Analysis Tool accounted for 1.63 percent.

Google search properties (Google.co.uk and Google.com) were used in 87 percent of U.K. searches in May, a 12 percent increase compared to May 2007.

Yahoo search properties accounted for 4.09 percent of U.K. searches in May, a 2 percent increase since April. MSN search properties accounted for 3.72 percent, and Ask search properties accounted for 3.07 percent. MSN searches increased 2 percent since April, and Ask searches increased 6 percent.

Comparing May 2008 to May 2007, Hitwise reported that sites in the travel, news and media, entertainment, business and finance, sports, online video and social networking categories saw double-digit increases in the percentages of traffic coming directly from search engines.