Early success for the iPhone 5 smartphone has helped Apple to overtake Google's Android software in the United States, research firm Kantar WorldPanel said on Tuesday.

Apple's US share of smartphone sales in the 12 weeks to October 31 more than doubled from a year ago to 48.1%, putting it within reach of the record 49.3% it managed in early 2012.

Android's share dropped to 46.7% from 63.3%, Kantar WorldPanel's data showed, but it continues to dominate in key European markets. The platform claimed 74% market share in Germany and 82% in Spain.

Android's combined share of the top five European markets rose to 64%, from 51% a in 2011, while Apple's share edged up by one percentage point to 21%.

Research In Motion Ltd saw its share fall in all but one of the surveyed markets, sliding to 1.6% from 8.5% in the United States, and to 2.7% from 8.7% in Brazil. In Germany, the BlackBerry maker's share rose 0.9 percentage points to 2.5%.

RIM's stock fell 5.9% to C$11.20 on the Toronto Stock Exchange. But the shares, which soared last week on rising optimism around RIM's soon-to-be-launched BlackBerry 10 devices, were still up more than 15% from last Monday's close.