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Android still leads in U.S., but iOS grows stronger

Sales jump 3.5 percent for iOS in the three-month period ending May, thanks in large part to T-Mobile, says Kantar Worldpanel ComTech.

HTC One, Samsung Galaxy S4, iPhone 5
The lion's share of the smartphone market is commanded by Apple's iOS and the iPhone (right) and by Google's Android, here made manifest by the HTC One (left) and the Samsung Galaxy S4. Josh Miller/CNET

Android remains the top dog for U.S. smartphone sales, though Apple's iOS is creeping up.

Google's mobile OS took home 52 percent of all U.S. smartphone sales from March through April, showing little gain from the same period last year, Kantar said on Monday.

At the same time, iOS grabbed 41.9 percent of smartphone sales in the U.S., an increase of 3.5 percent from a year ago. And Apple has T-Mobile to thank for at least some of that gain, according to Kantar.

"The highly anticipated release of the iPhone on T-Mobile has benefited iOS in the latest three-month period, though it has not yet impacted T-Mobile's share in the market," Dominic Sunnebo, global consumer insight director for Kantar Worldpanel ComTech, said in a statement.

The iPhone 5 was the top-selling smartphone at T-Mobile over the three-month stretch ending May, even though the carrier had only just launched the phone in mid-April. T-Mobile also managed to lure in a lot of first-time smartphone buyers.

Among all T-Mobile subscribers who picked up an iPhone from March through May, 53 percent upgraded from a feature phone, Kantar said. That compares with the average of 45 percent of iPhone buyers who jump from a feature phone. The iPhone also stands to gain more T-Mobile customers down the road. Among T-Mobile subscribers who plan to change their phones over the coming year, 28 percent are eyeing an iPhone.

Windows Phone remained in third place among U.S. smartphone sales with a 4.6 percent share. That was up almost 1 percent from the same three-month period in 2012 but down from the sales seen in the three months ending in April.