Thousands of proud new handheld-PC users may be putting their companies at risk as they connect their devices up to corporate systems for the first time.

According to Psion, around 75,000 people received handhelds for Christmas, and the company has warned businesses to put policies in place to prevent security and management nightmares as users attempt to connect to their corporate networks.

Psion said that risks to businesses include the loss of sensitive company information as users download data from their PCs, and network crashes as the extra data traffic generated by the devices causes bandwidth overload.

The company said its own research found 70 per cent of IT managers are also concerned about how to integrate mobile working and applications into office networks, so employees can work more efficiently and without compromising existing IT systems.

Psion warned that businesses risk not only security breaches, but overspending and inefficient working practices if they do not set down regulations and standards for users.

Wayne Sowery, special projects director at UK security consultancy MIS, said users should also be warned about the increasing risk posed by viruses on handheld devices.

"The first PC viruses were very basic and the first handheld viruses are the same. But given time, the level of sophistication in these viruses will grow. No-one saw the Melissa virus coming."

However, Sowery said one benefit of these devices being given as presents is that users value them more. "They are more likely to look after them than if they were given as part of a corporate package," he added.

"To protect against loss of sensitive information, users should use encryption and password protection in case of loss or theft," he said.