A Nielsen survey found 49.7 percent of mobile subscribers had a smartphone as of February, up from 36 percent a year ago, Mediapost.com reported Friday.
Android maintains a strong lead in mobile operating systems, with a 48 percent share of the market, followed by iOS at 32 percent, with BlackBerry phones representing 11.6 percent.
Apple is gaining market share over BlackBerry and other competitors, including Microsoft's Windows Phone platform, Nielsen said.
The Windows Phone OS could get a much-needed surge when AT&T launches Nokia's Lumia 900 in April, planning a strong campaign for the Windows Phone-powered smartphone priced at $99.99, Mediapost.com said.
The Nielsen figures are based on a survey of more than 20,000 mobile users.