According to a report in The Times newspaper, Microsoft President Steve Ballmer has been lobbying senior management at Motorola of the United States, Nokia of Finland and Sweden's Ericsson, with ideas for future mobile phones.

Microsoft President Steve Ballmer

Microsoft wants them to use its own operating system, Windows CE, rather than rival Epoc software, which the companies are developing with Psion in a joint venture known as Symbian.

The Times quoted Mr Ballmer as saying the phone companies would not let their small investment in Symbian stand in their way if they saw better opportunities arising from Microsoft ideas.

But Stephen Pang, UK public relations manager for Psion, said: "Obviously you can never discount the threat from Microsoft.

"However we have signed up four of the leading handset manufacturers.

"We are confident that we have a head start and that the Symbian technology is superior."

Finland's Nokia also pledged its commitment to the Symbian joint venture.

"Nokia is totally committed to Symbian as a shareholder and to Epoc technology," said Tapio Hedman, vice-president for communications for Nokia Mobile Phones.

E-mail on the move

As the use of mobile phones rockets, the telecommunications and computing industries are planning a new generation of handsets with built-in screens allowing e-mail and Internet access.

In the future people will use their phones to access the internet on the move

The market is expected to be vast, and Microsoft and Psion are vying to provide the operating system the phones will use.

Microsoft already dominates the traditional personal computer market with its Windows software, of which CE is a pared-down version.

But Psion, a market leader in portable palmtop computers, has been developing Epoc as a rival.

A week ago Psion recruited Japan's Matsushita Communication Industrial - the world's fourth largest cellular phone maker, with Panasonic among its brand names - to Symbian.