Dell is planning to sell its first convertible tablet PC later this year.

The PC maker revealed that it is working on the machine and showed a prototype of it on a company blog.

"I'm here to confirm we will enter the [tablet PC] market later this year," said Jeff Clarke, senior vice president of Dell's business product group.

The tablet PC will be targeted at the education, health care and corporate markets, he said. Clarke didn't offer any technical specifications of the machine but said it will be "one of the lightest weight" tablet PCs in the market. The version shown in the video was running Windows Vista.

"The technology and customer and usage models have evolved to the point where it makes it right for Dell to enter the marketplace," he said. "We're excited and everybody, we're coming."

Tablet PCs still only account for a fraction of the portable PC market but growth in the sector is expected to outperform the overall market over the next few years, according to IDC.

Shipments of convertible tablet PCs like that planned by Dell are expected to total 1.5 million units this year, IDC said in a December 2006 report. That's 1.4% of the entire market, which is expected to total 100.5 million units in 2007. Between 2005 and 2010 the portable market will grow at an annual average of 18.9%, while the convertible tablet market grows at 45.9% per year, said IDC.

Last week Fujitsu unveiled a convertible PC in Tokyo, aimed at business users. The FMV-U8240 is based on Intel's "McCaslin" ultra-mobile PC platform and is intended to serve as a secondary PC when workers are on the move. The machine has a 5.6-inch display and is small enough to fit into a jacket pocket. It will go on sale in mid-June and cost from ¥144,000 (£601.77).