The total number of U.S.-based searches conducted across approximately 60 search engines in December reached nearly 5.1 billion - or an increase of 55 percent from the 3.3 billion searches conducted in Dec. 2004, according to Nielsen/NetRatings. Google accounted for nearly half - 48.9 percent - of the searches, increasing its share by 5.7 percentage points from Dec. 04's 43.1 percent. Yahoo Search and MSN Search shares fell 0.3 and 3.1 percentage points, respectively.

Yahoo accounted for 21.4 percent of searches in December, and MSN Search was third with 10.9 percent.

The number of searches conducted on the top three search engines increased by double digits compared with December '04 numbers. Searches on Google increased 75 percent, to number nearly 2.5 billion; Yahoo searches increased 53 percent, to nearly 1.1 billion, and MSN Search searches increased 20 percent, to 553 million.