Worldwide smartphone sales to end users soared to 149 million units in the fourth quarter of 2011, a 47.3% increase from the fourth quarter of 2010, according to Gartner. Total smartphone sales in 2011 reached 472 million units and accounted for 31% of all mobile devices sales, up 58% from 2010.

Smartphone volumes during the quarter rose due to record sales of Apple iPhones. As a result, Apple became the third-largest mobile phone vendor in the world, overtaking LG. Apple also became the world's top smartphone vendor, with a market share of 23.8% in the fourth quarter of 2011, and the top smartphone vendor for 2011 as a whole, with a 19% market share.

"Western Europe and North America led most of the smartphone growth for Apple during the fourth quarter of 2011," says Roberta Cozza, principal research analyst at Gartner. "In Western Europe the spike in iPhone sales in the fourth quarter saved the overall smartphone market after two consecutive quarters of slow sales."  

The quarter saw Samsung and Apple cement their positions further at the top of the market as their brands and new products clearly stood out. LG, Sony Ericsson, Motorola and Research In Motion (RIM) again recorded disappointing results as they struggled to improve volumes and profits significantly.

Worldwide mobile device sales to end users totaled 476.5 million units in the fourth quarter of 2011, a 5.4% increase from the same period in 2010. In 2011 as a whole, end users bought 1.8 billion units, an 11.1% increase from 2010.

"Expectations for 2012 are for the overall market to grow by about 7%,while smartphone growth is expected to slow to around 39%," says Annette Zimmermann, principal research analyst at Gartner. 

Apple had an exceptional fourth quarter, selling 35.5 million smartphones to end users, a 121.4% increase year on year. Apple's continued attention to channel management helped it take full advantage of the strong quarter to further close the gap with Samsung, which saw some inventory build up for its smartphone range, according to Gartner. Apple's strong performance will continue into the first quarter of 2012 as availability of the iPhone 4S widens, per the research group. However, since Apple will not benefit from delayed purchases as it did in the fourth quarter of 2011, Gartner analysts expect its sales to decline quarter-on-quarter.

In the smartphone OS market, competition between Google and Apple intensified. Android's share declined slightly sequentially. This was due to strong iPhone sales, driven in particular by the iPhone 4S in mature markets and the weakness of key Android vendors as they struggled to create unique and differentiated devices.

Samsung remained the main contributor to Android share gains in the second half of 2011. iOS's market share grew eight percentage points year-on-year, but Gartner analysts expect Apple's share to drop in the next couple of quarters as the upgrade cycle to the iPhone 4S slows. Nokia's first Windows Phone smartphones, the Lumia 710 and 800, made their debut, but, as expected, sales weren't enough to prevent a fall in Microsoft's smartphone market share.