Worldwide shipments of PDAs and smartphones increased 57 per cent during the first half of 2006, totalling 42.1 million units when compared to the same period last year.

The statistics, released Monday by industry analyst Gartner, found that the smartphone market is experiencing exponential growth, increasing 75.5 per cent on last year with 34.7 million units shipped in the first half.

The smartphone market is now more than four times the size of the PDA market. PDA shipments increased by 5.7 per cent to reach 7.4 million units.

During the first half, Japan overtook Europe, Middle East and Africa to become the largest market for smartphones, accounting for 33 per cent of the worldwide smartphone market. Meanwhile North America remains the only region where sales of PDAs continue to outsell smartphones.

Gartner believes that consumer demand for PDAs is dwindling, especially with no new models released by Palm in 2006.

In fact, Palm was the only major vendor to lose market share during the first half, falling from an 8 per cent stake of the PDA and smartphone market in the first half of 2005 to a 5 per cent share in 2006.

BlackBerry maker Research In Motion (RIM) retained its leadership position in the global PDA market, with an increase of 13.5 per cent in sales from the same period last year. But the company also has its eye on the smartphone segment and is expanding out of its enterprise user base with the launch of the Pearl.

In the first half of 2006, RIM accounted for 6.5 per cent of the combined PDA and smartphone market. RIM smartphone shipments represent 36 per cent of all BlackBerry mobile devices, up from 9 per cent in the same period last year.

At the top of the ladder Nokia held onto its crown, accounting for 42 per cent of the combined PDA and smartphone market in the first half of 2006 and commanding half of the global smartphone market.

Motorola meanwhile accounted for 5.3 per cent of the combined PDA and smartphone market, although the company’s smartphone shipments grew 103.5 per cent in the first half of 2006, which represented the highest year on year growth among the top 5 vendors. Gartner believes this performance was driven by the success of Motorola’s Linux-based devices in China.

However, Motorola is not making significant progress with its Microsoft and Symbian-based smartphones, with shipments of the Motorola Q suffering, Gartner said.

According to the analyst, smartphone shipments are forecast to increase by 66 per cent to reach 81 million units in 2006, driven by consumer demand.