The research firm said on Friday it believes that both Symbian and Android will account for 59.8 percent of all mobile OS sales by the year 2014. It sees Apple's iOS, which powers the iPhone, iPad and iPod touch, coming in third place with a market share of 14.9 percent.
Even with annual sales half that of its competitors, Apple would still be selling 130 million units per year in Gartner's projections. To put that in perspective, Apple Chief Executive Steve Jobs revealed last week that his company has sold 120 million iOS devices in total since the iPhone launched in 2007.
Gartner sees the market share of iOS growing in 2011 to 17.1 percent, up from an anticipated 15.4 percent in 2010. The firm expects Apple to sell a total of 70.7 million iOS devices next year.
Last month, Gartner claimed that shipments of smartphones running Android had passed the iPhone, thanks to its availability on numerous carriers and devices.
This year, Gartner has projected sales of 47.5 million Android devices, good for a 17.7 percent market share, slightly edging out Apple. By 2014, that number is seen rising to 259 million, or a 29.6 percent share -- within spitting distance of Nokia's anticipated 30.2 percent market share.
"The worldwide mobile OS market is dominated by four players: Symbian, Android, Research In Motion and iOS," said Roberta Cozza, principal research analyst at Gartner. "Launches of updated operating systems such as Apple iOS 4, BlackBerry OS 6, Symbian 3 and Symbian 4, and Windows Phone 7 will help maintain strong growth in smartphones in 2H10 and 2011 and spur innovation. However, we believe that market share in the OS space will consolidate around a few key OS providers that have the most support from CSPs and developers and strong brand awareness with consumer and enterprise customers."
The company said that budget devices based on Android from handset makers including Samsung, Sony Ericsson, LG and Motorola will launch in the second half of 2010 and help to drive growth even further.
The firm sees open source platforms dominating more than 60 percent of the smartphone market by 2014, while "single-source platforms" like iOS and Research in Motion's BlackBerry OS will increase in sales, but at a rate below the market average. Gartner also sees Microsoft's Windows Phone relegated to sixth place, behind the MeeGo platform created by Intel and Nokia.