Sales internationally are expected to grow seven percent in 2016, to reach 1.5 billion units, according to the report from market research firm Gartner.
The expected growth in 2016 is down from 14.4 percent growth in 2015.
"The smartphone market will no longer grow at the levels it has reached over the last seven years. Smartphone sales recorded their highest growth in 2010, reaching 73 percent," said Anshul Gupta, research director at Gartner.
The report said the smartphone market had reached 90 percent penetration in the mature markets of North America, Western Europe, Japan and the Asia Pacific region, slowing future growth.
Also, the users in these regions were not replacing or upgrading their smartphone as often as in previous years.
"In the mature markets, premium phone users are extending life cycles to 2.5 years, which is not going to change drastically over the next five years," Gupta added.
Communications Service Providers (CSPs) have moved away from subsidies providing a free smartphone every two years, which had led to more varied upgrade cycles.
Since mature markets are saturated, the focus for many vendors is on India and China.
"India has the highest growth potential. Sales of feature phones totalled 167 million units in 2015, 61 percent of total mobile phone sales (are) in India," Gupta noted.
Smartphones are expensive for users in India. But with the average selling prices of low-end models falling, Gartner said 139 million smartphones would be sold in India in 2016, growing 29.5 percent year over year.
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