According to data released last week from Web analytics player WebSideStory, Google handles about 41 percent of all search engine referrals as of March 23. Compared to last year, WebSideStory reported that hits from the Google.com domain grew as a percentage of all search engine referrals, with an increase of about 5.01 percent.

At the same time -- and in spite of a slew of recent efforts aimed at boosting its position on the search scene -- Yahoo! continues losing ground. As the second-place provider of search referrals, Yahoo! posted a referral percentage of 27.40 percent -- down from 30.95 percent on the same day last year.

In third place remains Microsoft's MSN search engine, which provides about 19.57 percent of referrals. A year ago, MSN handled about 17.83 percent of all referrals.

San Diego, Calif.-based WebSideStory did not break out paid and unpaid searches in its data. The company said its findings were based on a sample size of more than 25 million unique browsers, tracked anonymously using its hosted HBX and HitBox Professional Web analytics services.

"Google's share of search referral in the U.S. continues to grow dramatically," said Geoff Johnston, a WebSideStory analyst who tracks global Internet user trends. "Google finally surpassed Yahoo! in late 2002 and the gap is widening. Yahoo! has made several strategic moves this year, but it remains to be seen if it can regain the ground it has lost."

A year ago, Google and Yahoo! were significantly closer -- Yahoo! referred about 30.95 percent of Web surfers to sites, while Google handled 35.99 percent. In 2002, however, the situation was reversed, with an emerging Google handling 28.86 percent of search referrals, compared to Yahoo!'s dominant 36.65 percent.

What the data doesn't indicate, however, are the factors behind the flip-flop. While it's likely that Google stole some traffic directly from Yahoo!, the scrappy search player's rise to dominance could also be due to searches that Google began handling due to the waning of rival search sites like AltaVista -- as suggested by the fact that Google (as well as MSN) saw an increase that exceeded Yahoo!'s lost traffic.

The new data comes as Sunnyvale, Calif.-based Yahoo! seeks to reinvigorate its place in the search market. Last year, the firm acquired search technology player Inktomi and paid search giant Overture. In February, the company launched a new search engine of its own, incorporating technology from its acquisitions -- and replacing Google, which had previously powered its search listings. It

Last month, Yahoo! also snapped up Kelkoo, a shopping-comparison engine serving the European market.

Christopher Saunders is managing editor of eCommerce-Guide.com.