Gartner also estimated that the number of smartphone units being sold globally will reach 468 million units by the end of the year.
Android will become the most popular operating system, as it will account for 49 per cent of the smartphone market by 2012, it was also estimated.
Roberta Cozza, principal analyst at Gartner, said: "By 2015, 67 per cent of all open operating system devices will have an average selling price of $300 (£183) or below, proving that smartphones have been finally truly democratised."
She added that Android's greatest volume opportunity will be in mid to low-cost smartphones, particularly in emerging markets.
Smartphones are now owned by around 17 million Brits, with 31 per cent of these downloading apps and 28 per cent playing games on the devices, a report by TNS Technology recently found.
From IAB