Android was the only smartphone operating system to gain U.S. market share in the third quarter, growing more than 10%, Nielsen said Thursday.

Smartphones running the Android OS were used by 43% of smartphone owners in the third quarter, up from 39% in the second quarter, based on Nielsen surveys of actual users.

Meanwhile, Apple, whose iPhone runs on iOS, remained the biggest single smartphone brand in the U.S. The iPhone had 28% market share in both the second and third quarters, Nielsen said.

The other smartphone platforms trailed Android and iOS in the third quarter: BlackBerry had 18%, down from 20% in the previous quarter; Windows Mobile had 7%, while Nielsen didn't say how the Windows Phone OS did in the third quarter after gaining just 1% in the second quarter. All other OSes combined had 4% of market share in the third quarter.

Nielsen also found that adults aged 25-34 years continued to be the biggest users of smartphones by far. Of that group using either a feature phone or a smartphone, 62% use a smartphone, while smartphone penetration is about 54% for ages 18-24 and 35-44, the next highest group.

This week, analyst firm Canalys said HTC shipped the most smartphones to the U.S. in the third quarter, shipping about 5.7 million units, with Samsung shipping 4.9 million units and Apple shipping 4.6 million. Globally, that means HTC finished fourth in smartphone shipments with 13.2 million smartphones. Samsung was the global leader with 27.3 million smartphones shipped in the third quarter, while Apple shipped 17.07 million and Nokia shipped 16.8 million, Canalys said.