Worldwide, Microsoft sites accounted for 14.5% of total minutes spent online in September, with Microsoft's Windows Live Messenger representing nearly 70% of time spent on the property during the month.
Google sites captured 9.3% of total minutes -- or about 2.5 billion hours -- with YouTube accounting for nearly half of total time spent at the property.
Yahoo sites, meanwhile, ranked as the third-most-engaging Web property at 1.7 billion hours, followed by Facebook.com at 1.4 billion hours. Facebook's share of attention reached 5.1% in September -- an increase of 2.9% points from the previous year -- as its continued growth in popularity precipitated this surge in share.
"Understanding the global Internet landscape is the first step towards executing effective marketing strategies in these growing markets," said Jack Flanagan, EVP of comScore Media Metrix. "With the U.S. economy only now emerging from a recession, many multinational corporations have shifted the focus of their growth strategies towards developing markets."
Overall, nearly 27 billion hours were spent online globally by a record online population of 1.2 billion Web users age 15 and older. "The Internet continues to be a dynamic and growing environment around the world with the global online population climbing more than 20 percent in the last year," Flanagan said.
A regional analysis of the top global properties in time spent by their visitors revealed different preferences across global markets. Yahoo sites captured the largest share of time in North America with 11.2% share, while also attracting a notable 7.9% share of time spent in the Asia-Pacific region.
Google sites commanded a strong share of time spent in Latin America -- at 19.4% -- Middle East and Africa -- 9.7% -- Europe -- 9.6% -- and North America -- 9.1%.
Microsoft Sites held the largest share of time spent among the top worldwide properties in Europe -- 16.8% -- Latin America -- 35.9% -- and the Middle East and Africa -- 33.1%.