Nokia will acquire Psion's stake in operating system developer Symbian and become the majority shareholder.
Nokia will pay a fixed sum of £93.5m and a variable payment of 84p for each Symbian OS-based device sold during 2004 and 2005. In return it will see its stake in Symbian rise from 32.2% to around 63.3%.
Psion estimated Symbian OS-based device shipments will be 18.7 million units in 2004 and 31.5 million units in 2005 to bring the total value of the transaction to around £135.7m.
The fixed payment will be made on completion of the deal and the variable payments made in March 2005 and March 2006. It also retains a right to a higher payout should an IPO (initial public offering) of Symbian take place before the end of 2005.
Completion is expected within the coming months but is subject to approval by competition authorities and Psion's shareholders.
Other shareholders in Symbian include Panasonic, Samsung Electronics, Siemens, Sony Ericsson and Ericsson.
Martyn William writes for IDG News Service