HELSINKI, FINLAND: Global mobile data traffic continued to surge in March at the fastest pace in 10 months, but in many countries the traffic is coming from old cellphone models, Internet browser firm Opera said.

Data traffic through Opera's mobile browser rose in March by 19.3 percent on the previous month, the fastest rate since May 2008, Opera said.

Wireless operators are keen on raising revenue from Internet browsing and the social networking boom as revenue from traditional voice calls is declining.

Data traffic on mobile operators' networks rose on average 4.7 times last year, with some operators seeing traffic surge more than 10 times, boosted by the uptake of wireless data cards in laptops, according to telecoms equipment firm Nokia Siemens.

Nokia Siemens and rivals Ericsson and Alcatel-Lucent, who have suffered over the last few years from aggressive pricing from Asian rivals like Huawei, are also looking for rising data traffic as a lead into new orders.

Opera has 23 million users of its Opera Mini browser who all access the Internet through Opera's servers -- giving the firm usage data -- and who generated more than 148 million megabytes of data traffic for operators worldwide in March.

Opera said in its monthly mobile Internet report Nokia's N70 model, a cheap smartphone introduced four years ago, was leading the list of top Internet traffic generating models in India, Indonesia and Nigeria.

The N70 was unveiled a few months after YouTube was founded and two years before Apple (AAPL.O) introduced iPhone.