Sales of Android-based smartphones may have outpaced those of Apple's iPhone in the U.S. last quarter, but globally the latter is still ahead of Google's platform by more than 3 million units. According to Gartner's latest figures, Apple's smartphone OS market share grew to 15.4% from 10.5%, taking the third spot in the list. But Android is gaining fast, and in fact it managed to leapfrog Microsoft Windows Mobile during this period with a jump from 1.6% to 9.6%.

Nokia's Symbian is still the largest smartphone platform by a wide margin, but it's not growing as fast as the competition. The company moved 24.1 million units, up from 17.8 million a year earlier, but its share slipped from 48.8% to 44.3%. Meanwhile, Research In Motion took the second spot dropping from 20.6% to 19.4%. In terms of actual phones, not just smartphone platforms, Nokia remained atop while RIM was fourth and Apple climbed to No. 7.

Overall, worldwide smartphone sales reached 54.3 million units during the fourth quarter, up a whopping 48.7% year-over-year. By contrast, mobile phones in general grew only 17% to 314.7 million units.