Global sales of smartphones to end users totaled 403 million units in the fourth quarter of 2015, a 9.7% increase on year, which was the slowest growth since 2008, according to Gartner. For all of 2015, smartphone sales reached 1.4 billion units, an increase of 14.4% from 2014.

In the fourth quarter of 2015, Samsung and Huawei were the only two top-five smartphone vendors to increase their sales to end users. Apple suffered its first decline in smartphone sales, with iPhone sales sliding 4.4% on year in the quarter.

With a 53% increase in sales in the fourth quarter of 2015, Huawei achieved the best on-year performance. Huawei's increased brand visibility overseas, and its decision to sell almost only smartphones, gave it a higher ASP in 2015, Gartner indicated.

For total smartphone sales in 2015, Samsung maintained the number one position with shipments totaling 320.22 million units, but its market share declined to 22.5% from 24.7% of a year earlier. Apple sold 225.9 million iPhones for a 15.9% share compared to 15.4% a year earlier. Huawei's smartphone sales approached 104.09 million units, up 53% on year, and its share grew to 7.3% in 2015 from 5.5% a year ago.

In terms of OS, Android increased 16.6% on year in the fourth quarter of 2015, to account for 80.7% of the global smartphone OS market, Gartner said.