
Statistics released by Web monitor ComScore revealed that Google properties attracted 156.3 million unique visitors during the month.
In comparison Microsoft sites racked up 144.1 million visitors, while the Yahoo network managed 99.5 million.
In addition to topping the charts, Google also had a higher share of surfers in Europe than the US.
"Google sites were visited by a greater proportion of the online population in Europe [75 per cent] than in the US [60 per cent]," said Bob Ivins, managing director of ComScore Europe.
During July, Google and Microsoft sites often vied for the first and second positions in 13 of 15 European countries, according to ComScore.
The web giants were often followed by a local company with a major national online presence in the third spot, such as France Telecom in France.
Rival monitoring firm Hitwise found that Google was the biggest search engine sending traffic to US shopping sites, driving 15 per cent of US visits to e-commerce sites for the week ending 26 August 2006.
Yahoo ranked second with almost five percent followed by MSN Search with 2.33 percent.
However, Hitwise noted that social networking site MySpace sent 2.53 per cent of all US visits to shopping sites in the same week. This compares with 1.28 per cent six months ago.
In that period, the market share of visits to MySpace.com has increased 67 per cent among all websites, and the site captured 4.88 per cent of all US visits for the week ending 26 August.
"Search is a proven method of acquiring traffic and Google is the leader in driving online retail site traffic," said Bill Tancer, general manager of global research at Hitwise.
"With the growth of MySpace and others, online retailers should expand their focus beyond search to consider social networking sites as a source of additional traffic."