• by Mark Walsh  @markfwal, March 3, 2011

The latest data from Nielsen shows Android edging ahead in the three-way battle for smartphone platform supremacy, with 29% share of the U.S. market in January compared to 27% each for Apple's iOS and BlackBerry. The new figures reflect the continued pattern of Android's ascendance, iOS holding roughly steady and BlackBerry losing ground.

At the start of 2010, Android had just 8% market share, compared to 29% for iOS and 36% for Research in Motion's BlackBerry. In December, Nielsen showed the three in a virtual three-way tie, while comScore had BlackBerry still ahead with 31.6% U.S. share compared to 28.7% for Android and 25% for iOS.

Worldwide, research firm Canalys reported in January that Android had overtaken long-reigning market leader Nokia's Symbian as the top smartphone platform in the fourth quarter. Handset manufacturers sold 32.9 million Android-powered phones in the fourth quarter of 2010 -- up sevenfold from a year ago, compared to Symbian sales of 31 million.

Since Android, unlike iOS and the BlackBerry OS, runs on phones made by multiple device makers, Nielsen looked at distribution of the Google operating system across different manufacturers. Android-powered phones made by HTC accounted for 12% of the market, while those from Motorola were 10%, Samsung, 5%, and "others," 2%.

The new data also showed younger users helping to drive Android's growth. The  Google platform had the largest share of smartphone users 18 to 25 years old, with 14%, compared to 12% for the iPhone, BlackBerry, 11%, Palm, 3%, and Microsoft, 2%.

Smartphones overall continue to gain in popularity, with nearly half (47%) of those who bought a mobile phone in the last six months choosing a phone with an operating system over a regular phone, according to Nielsen. The research firm has predicted that smartphone penetration in the U.S. will surpass 50% by the end of 2011.