Social networking use has nearly doubled in the past year, according to the research. Some 42 percent of internet users regularly visit sites such as Facebook and MySpace compared with just 23 percent this time last year.
Italians are the heaviest internet users, averaging 13.6 hours per week, followed by the Swedes at 13 hours and the French at 12.7 hours.
The British are the seventh heaviest users at 12 hours a week online, up from 11.3 hours in 2006.