* Apple more than doubles US market share to 48.1 pct
* Android still dominant in key European markets
* BlackBerry market share down everywhere but Germany (New throughout with market reaction, data on Research in Motion)
HELSINKI, Nov 27 (Reuters) - 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 U.S. share of smartphone sales in the 12 weeks to Oct. 31 more than doubled from a year ago to 48.1 percent, putting it within reach of the record 49.3 percent it managed in early 2012.
Android's share dropped to 46.7 percent from 63.3 percent, Kantar WorldPanel's data showed, but it continues to dominate in key European markets. The platform claimed 74 percent market share in Germany and 82 percent in Spain.
Android's combined share of the top five European markets rose to 64 percent, from 51 percent a year earlier, while Apple's share edged up by one percentage point to 21 percent.
Research In Motion Ltd saw its share fall in all but one of the surveyed markets, sliding to 1.6 percent from 8.5 percent in the United States, and to 2.7 percent from 8.7 percent in Brazil. In Germany, the BlackBerry maker's share rose 0.9 percentage points to 2.5 percent.
RIM's stock fell 5.9 percent 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 percent from last Monday's close. (Reporting By Tarmo Virki; Additional reporting by Allison Martell in Toronto; Editing by David Goodman and David Gregorio)