Symbian is losing dominance in the smartphone operating system (OS) market according to Gartner, with the analyst firm claiming that Symbian’s share of the global OS market decreased to 47.1 percent in the fourth-quarter of 2008. That’s down from its 4Q 07 share of 62.3 percent. “Pressure from new platforms entering the consumer space, the continued decline of Nokia’s smartphone sales and the weakness of the Japanese mobile device market have negatively affected Symbian’s share,” Gartner noted in a statement.

Meanwhile, RIM grew its year-on-year share of the global smartphone OS market to 19.5 percent in the fourth-quarter, up from 10.9 percent in the year-earlier period (a huge yearly growth rate of 84.9 percent). Microsoft’s Windows Mobile retained its third position, increasing market share over the period by 0.5 percent, to 12.4 percent. This was mainly driven by the popularity of Samsung’s Omnia device and touchscreen products from HTC. Apple’s iPhone pushed the Mac OS X platform to fourth place, with 10.7 percent market share (up from 5.2 percent in 4Q 07). This was the largest growth rate recorded by any of the platforms (111.6 percent year-on-year growth). Linux enjoyed a 19.4 percent growth rate over the year, to a Q4 08 share of 8.4 percent. This growth was partly fuelled by the high profile launch of the first Android-powered handset, the HTC G1, sold via T-Mobile. Gartner estimates that Android smartphones accounted for 20 percent of total Linux sales in the fourth quarter of 2008. Finally, Palm’s struggles continued, with the firm’s Palm OS market share falling from a 1.2 percent share in 4Q 07 to 0.9 percent in the year-later period. Palm is hoping its new mobile operating system, webOS, and touchscreen phone called Pre will help turn around company fortunes. Pre is due for launch via US operator Sprint by the end of June.