Android remains the most popular smartphone operating system in the U.S., but its market-share among new purchasers has stalled, research firm Nielsen reports.
According the Nielsen's May survey, 27 percent of cell phone purchasers from March through May bought an Android-powered device, the same percentage from December through February.
(Also see: Who's winning in U.S. smartphone market?
But the iPhone recorded a big increase in the latest three-month period, with 17 percent of cell phone purchasers opting for the Apple device, versus only 10 percent from December through February.
Overall, Android devices still are the most popular in the U.S., used by 38 percent of all smartphone users. Apple is No. 2 with 27 percent, with Research in Motion's BlackBerry OS at No. 3 with 21 percent and falling.
At the beginning of the year, the three mobile OSes were in a virtual tie.
Apple's strong showing in recent months no doubt is due primarily to the introduction of the Verizon iPhone in February. Previously AT&T was the only carrier allowed to sell iPhones in the U.S.
Only 6 percent of U.S. consumers purchasing a cell phone from March to May opted for the BlackBerry, slightly more than half the 11 percent from the previous three-month period. Don't count on that trend reversing itself in the August survey.
Further, Nielsen said, smartphones for the first time are the device of choice for buyers of mobile handsets. Nielsen's May survey shows that 55 percent of purchasers over the three-month period measured bought a smartphone, up from 34 percent last year.