Apple's iPhone is the world's most popular smartphone accounting for 23.8 percent of all smartphones sold during Q4 of 2011, says Gartner.

According to the research firm, 149 million smartphones were sold across the globe during Q4, meaning across 2011 as a whole 472 million devices were sold, with Apple's iPhone accounting for 19 percent of these. Furthermore, smartphone sales made up nearly a third (31 percent) of all mobile devices sold during 2011.

Gartner also said Apple became the third largest vendor of mobile devices behind Nokia and Samsung, ousting LG to fourth place.

"Western Europe and North America led most of the smartphone growth for Apple during the fourth quarter of 2011," said 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."

Gartner said after Apple, ZTE and Huawei were the fastest-growing vendors in Q4.

"These vendors expanded their market reach and kept on improving the user experience of their Android devices," said Cozza.

However, when it comes to the smartphone OS, Google's Android came out trumps, accounting for 50.9 percent of all smartphones sold in Q4 of 2011, while Apple's iOS is running of 23.8 percent of all the Q4 handset sales. Research In Motion slipped to fourth place behind Symbian, accounting for just 8.8 percent, a 5.8 percent decrease on the same period in 2010. This contradicts recent claims by the manufacturer that BlackBerry was the best selling smartphone brand in the UK,

In January, RIM cited figures from GfK that claimed BlackBerry was responsible for 26.3 percent of all smartphone sales during December 2011. Furthermore, the figures also revealed that on average across the whole year, BlackBerry accounted for 27.7 percent of the market, which RIM says makes it the best selling smartphone brand in the UK for the second year running.

"Expectations for 2012 are for the overall [mobile device] market to grow by about seven percent, while smartphone growth is expected to slow to around 39 percent," said Annette Zimmermann, principal research analyst at Gartner.