NEW YORK: Social networks such as Facebook and Twitter are seeing usage levels continue to rise in major markets around the world, research from The Nielsen Company has found.

Across the ten countries studied by Nielsen, the average web user spent 5 hours 27 minutes on these sites at home and work in February, an increase of over two hours on an annual basis.

The Italian panel posted the highest figure, on 6 hours 27 minutes, ahead of their counterparts in Australia, on 6 hours 25 minutes, and the sample in the US, on 6 hours 2 minutes.

The United Kingdom was in fourth position, on 5 hours 51 minutes, with netizens in Spain, which completed the top five, a further ten minutes behind.

Brazil's online population posted 4 hours 28 minutes, some 15 minutes longer than their peers in France, 40 minutes more than in Germany, and an extra hour when compared with participants in Switzerland.

Despite being home to some of the most digitally-literate consumers in the world, Japan registered the lowest score, on 2 hours 37 minutes.

Overall, the number of unique visitors to social networking services climbed from 244.2 million to 314.5 million year-on-year in February.

The US contained just under half of this audience, or 149.3 million people, up from 115 million people recorded 12 months previously, and from 105 million in the same month in 2008.

Facebook boasted the largest reach in the ten nations featured in Nielsen's study, on 51%, with the typical user logging in around 19 times in February, and spending 5 hours 52 minutes on its pages.

The world's biggest social network recently announced it had 400 million members worldwide, including 100 million who regularly accessed its portal via their mobile phones.

However, Nielsen's approach tracked the "active" users of each platform over the assessment period, rather than basing its findings on the total number of individuals who had joined these properties.

MySpace enjoyed a reach of 15% in February, with a normal dwell time of almost an hour, spread across nearly seven separate sessions.

Twitter was the third most popular service, receiving 31.4 million visitors, who devoted 36 minutes posting and reading "tweets" over the course of 5.8 trips to its site.

LinkedIn, in fourth, attracted 6% of the potential social networking audience in February, with the usual panellist returning 3.15 times in February, for 13 minutes in all.

Classmates Online, in fifth, had a slightly smaller share than LinkedIn, on 5%, but marginally out-performed its business-orientated rival in terms of the sessions and time recorded per person.

Data sourced from The Nielsen Company; additional content by Warc staff