Psion shareholders have approved the sale of the company's 31 per cent stake in Symbian to mobile phone giant Nokia.

The deal will allow Nokia to take a 63 per cent controlling stake in the Symbian mobile operating system.

The decision came today at an Extraordinary General Meeting called by Psion, but met with opposition from Phoenix Asset Management, the company's biggest investor.

Psion has invested £29m in Symbian since its creation, but estimates that proceeds from the sale will exceed £135m.

Alistair Crawford, chief executive of Psion, said in a statement: "The task now is to grow the Psion Teklogix business."

Psion Teklogix manufacturers handheld PCs for mobile computing and wireless data collection. The company last week unveiled its rugged Workabout Pro device for use in factories and retail environments.

But IT analyst firm Ovum raised doubts over whether Symbian would remain vendor-neutral after Psion's share sale.

"If Nokia was to gain a majority share of Symbian it would not necessarily be a good thing for either the operating platform or the industry," warned Jessica Figueras, senior analyst at Ovum.

"There has always been a suspicion that Nokia was a back-seat driver, but Symbian has done well to show neutrality until now."