Google's Android software ran on more than half of all smartphones sold in the third quarter as consumers snapped up handsets made by Samsung Electronics.
The Google system accounted for 52.5 per cent of smartphone sales, more than doubling its share from a year earlier, researcher Gartner said.
Even as some consumers delayed purchases to wait for Apple's latest iPhone and other models, smartphone sales grew 42 per cent, it said.
"Android benefited from more mass-market offerings, a weaker competitive environment, and the lack of exciting new products on alternative operating systems," said analyst Roberta Cozza.
Smartphones gained one percentage point from the previous quarter to 26 per cent of all mobile-phone sales. Nokia's Symbian handsets lost almost 20 percentage points from a year earlier to account for 16.9 per cent of smartphones as the company shifted to Microsoft's Windows platform.