Kantar Worldpanel on Monday released its latest analysis of the U.S. smartphone market for the three month period ending May 2013, finding that Apples iOS platform held 41.9 percent of sales. That figure is up 3.5 percent from the same period last year.
Google's Android operating system remained the overall leader in smartphone share at 52 percent, up only 0.1 percentage points by Kantar's estimate. Microsoft's Windows Phone platform saw its market share jump, posting a market share of 4.6 percent, up 0.9 percent over the same period last year.
Kantar's report attributes the iPhone's share growth in no small part to the device's launch on T-Mobile in April. The launch date for the device on that carrier saw considerable lines, and executives described a "gangbusters first day of sales."
The iPhone in its assorted models accounted for 31 percent of T-Mobile's smartphone sales in the United States since its launch. Apple's bestselling smartphone accounts for more sales at T-Mobile's competitors, with the device accounting for 60.5 percent of AT&T's smartphone sales and 43.8 percent of Verizon's.
The Apple phone may continue to grow in importance on T-Mobile. Kantar's survey of the carrier's customers found that, among those planning to change devices in the coming year, fully 28 percent planned to upgrade to an iPhone.
Kantar's study also looked at smartphone sales among the major U.S. carriers, finding that there has been little movement among them. Verizon led the way with 34.6 percent of smartphone sales in the quarter, while AT&T came in second at 29 percent. Sprint accounted for 12.7 percent, and T-Mobile pulled in 10.1 percent. Despite gaining the iPhone, T-Mobile's share of smartphone sales was actually down 3.4 percent compared to the three months ending May 2012.
Google's Android OS powers the majority of both phones made and phones in the hands of consumers worldwide. Apple, though, is the sole manufacturer for devices running iOS, and the Cupertino company hauls in the lion's share of profits for the entire smartphone industry.