SAN FRANCISCO - Latest market research results released Thursday showed that almost half of US mobile subscribers now own smartphones, as of February.

According to data from research firm Nielsen, some 49.7 percent of US mobile phone users now have smartphones as of February, an increase of 38 percent over the same period last year.

The growth is driven by increasing smartphone adoption, as more than two-thirds of those who acquired a new mobile device in the last three months chose a smartphone over a feature phone, said Nielsen.

Among mobile platforms, Google's Android continues to be the market leader in the United States with 48 percent of smartphone owners saying they owned a device powered by Android operating system. Around 32.1 percent of the smartphone users have an Apple iPhone while Blackberry users accounts for 11.6 percent of the smartphone market.

As for smartphone buyers within the last three months, 48 percent of those surveyed in February said they chose an Android phone while 43 percent bought an iPhone.

The growth of Android and Apple's iOS was at the expense of Blackberry which was down to 5 percent of smartphones bought in the last three months. The other mobile platforms, including Microsoft's Windows Phone, only accounted for 4 percent of purchased smartphones.