In 9 weeks, iPhone share of US smartphone sales grew 17.5% by Philip Elmer-DeWitt @FortuneMagazine December 21, 2012, 7:56 PM EST E-mail Tweet Facebook Google Plus Linkedin Share icons FORTUNE — It’s been exactly three months since Apple AAPL launched the iPhone 5, and the effect on the data released Friday by Kantar Worldpanel ComTech couldn’t be clearer — at least in the U.S. In the 12 weeks ending Nov. 25 — including Black Friday, but not Cyber Monday or the three weeks in December when Apple’s supplies finally caught up to demand — the iPhone registered its highest-ever share of the U.S. smartphone sales: 53.3%, up from 35.8% a year earlier. “Apple has reached a major milestone in the US by passing the 50% share mark for the first time,” said Kantar’s Dominic Sunnebo, “with further gains expected to be made during December.” Most of Apple’s share came out of Google’s GOOG and Research in Motion’s RIMM hides. In the same 12 weeks, Android’s share of U.S. sales in the 12-week period fell to 41.9% (from 52.8% last year), and BlackBerry’s fell to 1.4% (from 7%). Among Apple’s competitors, only Microsoft MSFT managed to gain any traction, growing its U.S. share to 2.7% from 2.1%. The picture looks quite different in the rest of the world, especially in countries where the iPhone ‘s arrival was delayed. Although Apple’s share grew in Europe and Asia, Android’s gains were bigger. See chart below, courtesy of Business Insider. Click to enlarge. Via Business Insider.