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.
Samsung, provider of the Galaxy line of Android smartphones, became the biggest smartphone maker for the first time. "The entry-level Android smartphones are getting better and better," Cozza said. "This lower end is really what will be driving more growth next year."
The global mobile handset market gained 5.6 per cent in the third quarter to 440.5 million phones, Gartner said. It slowed from 35 per cent growth reported a year earlier and 16.5 per cent in the previous quarter.
Nokia retained the top spot with a 23.9 per cent market share, climbing from 22.8 per cent in the second quarter. Samsung, LG Electronics, Apple and ZTE rounded out the top five vendors.
"The rate of growth in smartphones has definitely slowed down in Western Europe and the US," Cozza said. "The fatigue in demand is partly due to the economic uncertainty, but consumers also want to wait until the fourth quarter to get more from the promotions and new devices that are available now."
She said smartphone growth slowed from 74 per cent in the second quarter although China and Russia continued to grow strongly.
Gartner forecasts 50 per cent growth in smartphones for the year and 11 per cent growth in the handset market overall. The company is revising its European forecasts downward as sales declined 19 per cent in Italy and 8 per cent in Germany.