Google's Android platform was used on four of five smartphones sold worldwide in the third quarter, while Microsoft's Windows Phone showed strong gains, said a survey out yesterday.

Android's market share rose to 81 percent, extending its lead over Apple's iOS, used on its iPhones, said the IDC survey. Android's share a year ago was 74.9 percent.

Even though iPhone sales grew 25.6 percent from a year earlier, the growth was slower than the overall market and Apple's share fell to 12.9 percent from 14.4 percent in the same period of last year.

Windows Phone emerged as the No. 3 smartphone platform with a market share of 3.6 percent, up from 2 percent a year earlier.

Windows Phone sales grew 156 percent, with more than 90 percent made by Nokia, the Finnish group whose handset division is set to be acquired by Microsoft.

BlackBerry, meanwhile, saw its troubles deepen as its market share fell to 1.7 percent from 4.1 percent a year ago. BlackBerry sales plunged 41.6 percent from a year ago despite the introduction of the new BlackBerry 10 operating system.

The overall market for smartphones surged 39.9 percent annually in the quarter to 261 million units.

The average selling price of a smartphone fell 12.5 percent in the quarter to US$317, IDC said.

"Android and Windows Phone continued to make significant strides in the third quarter. Despite their differences in market share, they both have one important factor behind their success: price," said IDC analyst Ramon Llamas.

"Both platforms have a selection of devices available at prices low enough to be affordable to the mass market, and it is the mass market that is driving the entire market forward."

IDC noted that Apple's market share was likely affected by weak sales ahead of the introduction of two new iPhone models in September, at the end of the quarter. But it sold 9 million of the new devices in the first weekend, suggesting a strong fourth quarter, IDC said.