Worldwide shipments of PDAs reached a record 3.7 million units during the second quarter, up 2.7 per cent from the same period a year ago, according to industry analyst Gartner.

Interestingly, much of the growth in the PDA market was generated by vendors that were not among the first-tier one year ago, while market leaders such as Palm, Research In Motion (RIM), HP and Dell have seen their market share slip or remain flat.

Despite a market share decline of 1.1 per cent during the quarter, RIM was still the worldwide leader, accounting for 22.5 per cent of worldwide PDA shipments.

Palm’s PDA shipments declined 27 per cent from the same period last year., but Gartner notes that Palm has not introduced any new PDAs since late 2005 and is focused on the Treo instead.

When looking at the PDA market, Gartner defines a PDA as a data-centric handheld computer primarily designed for use with both hands. Smartphones on the other hand are voice-centric and are designed for primarily a one-handed operation.

In fact, Palm’s Treo shipments totaled 656,000, but these are excluded from Gartner’s PDA numbers because they are smartphones. Meanwhile, RIM shipped nearly 1.3 million BlackBerry units, however, 467,000 units are excluded from this analysis because the BlackBerry 71xx models are classified as smartphones.

HP’s iPAQ continued to struggle as shipments fell 15 per cent. Although the new iPAQ 69xx series began shipping in Europe in July.

Newcomer Mio Technology, which is pushing a PDA product line focused on GPS navigation, is now the largest PDA vendor in Europe, and ranks second behind HP in the Asia Pacific region.

In terms of PDA operating systems, Microsoft’s Windows Mobile extended its lead over other PDA platforms, accounting for 54.2 per cent of PDA OS shipments. RIM OS accounted for 22.5 per cent of the market, followed by Palm OS at 13.4 per cent.

Todd Kort, principal analyst in Gartner’s Computing Platforms Worldwide group said: “There are quite a few more cellular PDA models with keyboards in the market now than there were one year ago, but none are seriously challenging RIM’s strong position in enterprise accounts.”

The average selling price of PDAs also fell by 6 per cent from one year ago to $373, mostly due to aging product lines, the increasing impact of wireless operator subsidies and relatively few new PDAs being launched. As a result, worldwide PDA end-user revenue fell by 4.1 per cent from one year ago to $1.38bn.