• by Mark Walsh  @markfwal, July 8, 2013

Apple’s iOS gained ground on Android during the three months ended in May, according to the latest figures from Kantar Worldpanel ComTech. iOS represented 41.9% of all U.S. smartphone sales during the three-month period, up from 38.4% a year ago. That marks the biggest gain by any mobile operating system for the period in question.

Android’s share was virtually unchanged at 52% of all smartphone sales. Fighting for a very distant third place behind iOS and Android, Microsoft’s Windows Phone increased its share to 4.6% from 3.7%, while ailing BlackBerry sank from 4.6% to 0.7%.

Separate data released by comScore last week showed Android was running on 52.4% % of U.S. smartphones through May, followed by iOS, with 39.2%, BlackBerry (4.8%), Windows Phone (3%) and Symbian (0.4%).

When it comes to wireless carriers, Verizon led the way with 34.6% of U.S. smartphone sales, trailed by AT&T Mobility (29%), Sprint (12.7%) and T-Mobile (10.1%). T-Mobile, which began selling the iPhone in April, saw its share fall the most -- from 13.4% a year ago -- while Verizon was the biggest gainer, increasing more than 2.6 points from 32%.

“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," noted Dominic Sunnebo, global consumer insights director at Kantar Worldpanel ComTech.