Sales of handheld devices fell below 1.5 million in the first quarter, the ninth consecutive quarter that worldwide shipments of PDAs have declined, according to an IDC study.

First quarter shipments of handheld devices totalled 1.47 million, down 22.3 percent from the same quarter a year ago, IDC said.

The demand for handheld devices will stop falling eventually, said IDC analyst Ramon Llamas.

At a certain point, demand will be sustained by core users who are attracted to new enhancements, such as Bluetooth, Wi-Fi, expandable memory and integrated GPS, he said.

IDC defines handheld devices as pocket-sized electronics that lack telephony, might have wireless e-mail, offer a stylus or keypad for data entry and are capable of synchronising data with a laptop or desktop PC.

The decline affected all the major vendors, so the segment leaders did not change from recent quarters.

Palm leads the sector with 32.2 percent market share, followed by Hewlett-Packard with 23.5 percent, Dell with 9.7 percent and Acer with 7.5 percent.

The only change was in the fifth spot, where Mio Technology reversed the market trend by posting an 84.4 percent gain in handheld shipments, compared to the first quarter of 2005. That performance pushed it past Medion in the rankings.

The news isn't all bad. Vendors say handhelds still serve as a low-cost way to attract new users.

At Palm, the combined sales figures for handhelds and smart phones continue to grow, said company spokesman Jim Christensen.

"The handheld business is not only profitable but it is growing our installed base, who will later upgrade to a higher-end handheld or a Treo smart phone, which is a great thing," he said.

Sixty percent of users who have never owned a PDA choose Palm's US$99 Z22 model as their first handheld, Palm claims.

Palm values that stream of new users so much that the company decided in May 2005 to renew its five-year contract for the Palm OS, he said.