Global shipments of handheld computers rose 18.4 per cent to 17.7 million in 2006, with Research in Motion Ltd.'s BlackBerry showing strong growth, but Palm Inc. suffering a steep decline in sales and market share, Gartner Inc. reported Tuesday.

In terms of operating systems for personal digital assistants (PDAs), shipments of devices based on Microsoft Corp.'s Windows platform grew by 38.8 per cent to nearly 10 million. Those shipments, by multiple manufacturers of Windows-based devices, increased Microsoft's market share to 56.1 per cent, up from 47.9 per cent in 2005, the research company said.

BlackBerry retained the top spot for PDA devices shipped, growing 10 per cent to 3.5 million for the year, but its market share slipped from 21.3 per cent in 2005 to just a shade below 20 per cent during 2006, Gartner said.

Palm saw PDA shipments slide by 29 per cent to less than 2.8 million devices, its market share plummeting to 11.1 per cent from the prior year's 18.5 per cent, Gartner said.

Hewlett-Packard Co.'s shipments also declined in 2006, falling 24.1 per cent to 2.3 million devices. Its market share fell by more than a third to 9.7 per cent versus the prior year's 15.1 per cent, according to the report.

Big demand for wireless

Gartner said the overall increase in shipments of PDAs was driven by growing demand for wireless access to e-mail and the internet. The research company found that 60 per cent of the devices shipped were equipped with cellular connectivity, up from 47 per cent in 2005.

The report has raised some eyebrows, because the company's data draws certain distinctions between PDAs and so-called "smart" cellphones that not all market observers agree with. TheRIM numbers, for example, include only its top-end 8700 line of devices, which work as e-mail gadgets, organizers and cellphones. Not included are more consumer-oriented BlackBerry 7100s and Pearls that boast many of the same features other than a full keyboard.

By contrast, Gartner's Palm tally does not include the Treo, a high-end organizer and phone that competes directly with the BlackBerry 8700. And while the T-Mobile Sidekick owes its success to consumers who mostly use it for text messages and phone calls, that device made by Sharp Corp. is included in Gartner's PDA tally.

Compared with cellphones, PDAs remain a tiny market. Another market research company, IDC, recently reported that cellphone makers shipped more than 1 billion handsets for the first time in 2006, up 22.5 per cent.