• by Mark Walsh  @markfwal, February 6, 2012

The worldwide smartphone market grew 54.7% last year, powered by sales of the iPhone 4S. Full-year smartphone sales grew at an even faster rate--61.3%--for a record 491.4 million units shipped worldwide. Still, that growth rate was below the 75.7% rate of 2010, according to research firm IDC. Although 2011 marks a slowdown as smartphones proliferate, 2012 is expected to be another double-digit year for growth.

By the end of the fourth quarter, one of out every three mobile phones shipped was a smartphone, noted IDC. Many of those of were iPhones. Apple said it sold 37 million of the devices in the last quarter of 2011, driven by demand for its latest model featuring voice-activated assistant Siri. While models like the iPhone 4S and Galaxy Nexus grab most of the attention, IDC said a growing number of Android-based phones selling for less than $250 also helped propel smartphone growth.

Apple edged out Samsung for largest market share among smartphone makers in the fourth quarter, 37% to 36%. But for full-year 2011, Samsung just nipped Apple, 19.1% to 19%, by nearly doubling its share from 7.5% a year earlier through sales of high-end and mid-tier Android devices.