Apple's iPhone made major inroads among recent buyers in its battle against smartphones running Google's Android, but still lagged behind its OS rival, pollster Nielsen said today.

In a December 2011 survey of U.S. consumers who had purchased a smartphone in the previous three months, 44.5% chose an iPhone, a jump of nearly 20 percentage points from the 25.1% that Nielsen measured in October.

That represents a 77% increase in the iPhone's numbers.

But Android retained the lead in the recent-buyers game with a 46.9% share, down from October's 61.6%.

A majority of the new iPhone owners -- 57% to be exact -- bought an iPhone 4S, the newest model in Apple's line-up, said Nielsen. The iPhone 4S debuted in the U.S. on Oct. 14, 2011.

Nielsen said the iPhone 4S had an "enormous" impact on Apple's huge jump in share among new smartphone purchasers.

And Apple remains significantly behind Google in the battle for total smartphone share, with just 30% of all smartphones running iOS in late 2011. Android, meanwhile, accounted for 46.3% of the operating systems used by all smartphone owners.

Nielsen's data showed that Microsoft's Windows Phone 7 has yet to join the race: Its December 2011 share was only 1.3%.

The pollster's numbers were in line with the most recent data from Internet metrics firm comScore, which last month said Android accounted for 46.9% of all U.S. smartphones in use during November 2011. Apple's share was 28.7%.

Although neither Apple or Android smartphone manufacturers regularly release sales figures for the U.S., analysts expect that next week Apple will say it sold more than 30 million iPhones worldwide in the final quarter of 2011.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@computerworld.com.

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