By the end of 2011, Android will be the most popular operating system worldwide, accounting for 49% of the smartphone market.
The research group expects worldwide smartphone sales to reach 468 million units in 2011, a 57.7% increase from 2010.
"By 2015, 67% of all open OS devices will have an average selling price of $300 or below, proving that smartphones have been finally truly democratised,” said Roberta Cozza, principal analyst at Gartner.
"As vendors delivering Android-based devices continue to fight for market share, price will decrease to further benefit consumers”, Cozza continued. "Android's position at the high end of the market will remain strong, but its greatest volume opportunity in the longer term will be in the mid- to low-cost smartphones, above all in emerging markets.”
Gartner predicts that Apple’s iOS will remain the second biggest platform worldwide through 2014 despite its share deceasing slightly after 2011.
"This reflects Gartner’s underlying assumption that Apple will be interested in maintaining margins rather than pursuing market share by changing its pricing strategy,” says Gartner who believes that Apple’s strategy will ultimately limit adoption of iPhones in emerging regions.
Research In Motion’s share over the forecast period will decline, "reflecting the stronger competitive environment in the consumer market, as well as increased competition in the business sector.”
Gartner also predicts that Nokia will push Windows Phone "well into the mid-tier of its portfolio by the end of 2012, driving the platform to be the third largest in the worldwide ranking by 2013.”
Gartner has revised its forecast of Windows Phone’s market share upward, based solely on Microsoft’s recent alliance with Nokia.
"Although this is an honourable performance it is considerably less than what Symbian had achieve in the past underlying the upward battle that Nokia has to face,” said Gartner.
Update: Gartner has dropped us a line with an overall smartphone forecast for Australia and New Zealand, but it's not split out by operating system.
In Australia, sales of smartphones (open OS devices) will account for 62% of all mobile handset device sales in 2011, and are expected to reach almost 10 million in 2015, when they will account for 79% of the total mobile device market.
In New Zealand, sales of smartphones (open OS devices) will account for 50% of all mobile handset device sales in 2011, and are expected to surpass 1.3 million in 2015, when they will account for 70% of the total mobile device market.
Tablet trivia fans might also like to know that next week Gartner will publish its first media tablet forecast by operating system.