Google has overtaken Microsoft to become the world’s most visited internet property, according to figures for March from comScore.

Google had 528m unique visitors last month, a rise of 5% on February’s figures, while closest rival Microsoft had 537m visits.

Meanwhile, Google was named the most valuable global brand this week by a Millward Brown/Financial Times study, valued at $66.4bn, ahead of General Electric on $61.9bn and Microsoft on $55bn.

Both events confirm the importance of Google, with its massive growth propelling it past many established brands and companies.

In a statement, Google said:

“Our goal has always been to provide the best online experience for our users. We build products based on user needs and input, which is part of what makes Google unique and results in a great online experience.”

Microsoft has been the most popular web property in every month since comScore began tracking these statistics in January 2006.

Among the reasons given for Google leapfrogging Microsoft was its acquisition of YouTube, and its popularity in Europe, as well as its core search business. Google had a 71.6% share of the global search market between August 2006 and January 2007.

Microsoft’s growth, by comparison, has been sluggish in recent years. It simply hasn’t been adding users fast enough to keep up with Google.

While Google leads Microsoft on unique visitors, the search engine still trails when you look at time spent on its internet properties. Global users spend an average of 12.8 minutes on Microsoft’s sites, compared to just 4.6 minutes on Google’s.

According to comScore’s Andrew Lipsman:

“Google’s position as the most-visited worldwide property is a testament to the continued growth of the search market. It also reflects the dramatic traffic growth to during the past year, which now reaches more than 160 million visitors worldwide.”