Google accounted for 59.3 percent of the volume of searches in the U.S. for May 2006, followed by Yahoo and MSN with 22.0 and 12.1 percent, respectively, Hitwise announced yesterday. The other search engines tracked by the online competitive intelligence firm accounted for the remaining 7 percent of U.S. searches.

Google's share increased from 58.6 percent in April and 58.3 percent in March. Yahoo's search share decreased from 22.2 percent in April and 22.3 percent in March. MSN's share of U.S. search decreased from April's 12.6 percent and 13.1 percent in March.

"As the volume of searches stabilizes across the top three search engines, the battle to supplement search with additional services and win the loyalty of internet users becomes critical," said Bill Tancer, general manager of global research at Hitwise.