Tablet PCs with a version of Windows XP have made a promising start in terms of sales. Despite high prices, many firms are buying, or plan to buy, the pen-input computers.

Toshiba would not disclose sales figures but said 11 percent of its business-to-business products are Tablet PCs. The firm added that 46 percent of its "thin and light" segment products were Tablets. Over 100 companies are seeking evaluation models from the Japanese giant.

Market watchers said the percentages seemed impressive considering that Toshiba's Portege 3500 tablet was only launched in November, a graveyard period for business sales. Fujitsu Siemens, which has over half the UK market for pen-based tablet devices according to market analyst IDC, was also upbeat. The firm already includes blue-chip firms such as Ordnance Survey, Unilever, Lindt, Wella, Gillette and L'Oreal among its pen PC customers.

The company said that Tablet PCs were attracting particular interest from market research, salesforce automation and utilities sectors. Large customers plan to run 500 to 1,000 pen tablet units, translating into #1m-plus contracts.

"I'm a little bit surprised," said Dave Cullinane, Fujitsu Siemens UK managing director. "It's bigger than we thought."

Chris Plank, hosting and security manager for ISP Scotland Online, is evaluating an NEC Tablet PC. "It will ease my life," Plank said. "I go to meetings where I make notes and have to re-key them. With this I can save my handwriting or convert it."

However, the limited specifications of Tablet PCs have deterred others.

"It's a great format but we decided against it because of lack of processing power and RAM capacity," said Joe Baguley of Quest Software, who considered supplying Tablet PCs to technical sales staff for product demonstrations.

"Our people are real road warriors and the software they run is demanding."

Some industry watchers have been pessimistic about the prospects for tablets, noting high prices and the fact that similar formats have previously failed to catch on. In November, analyst firm Gartner Dataquest predicted that Tablet PC shipments would reach 425,000 units in 2003 - just 1.2 percent of worldwide notebook shipments.

However, experts close to the Tablet PC business said that prediction could fall short. "Manufacturers' original estimates might have been low," said Mark Erickson of Phoenix Technologies, which makes Bios software for the devices. Erickson predicts Tablet PC sales of up to 750,000 this year.