Worldwide sales of smartphones grew at the slowest pace in two years as demand in China declined for the first time ever, a new report by research firm Gartner showed Thursday.

According to the study, second-quarter sales were up 13.5 percent to 330 million units from a year earlier.

While the appetite for smartphones continues to grow in emerging markets in Eastern Europe, the Middle East and Africa, Chinese consumers appear to have gone on a diet, with demand there down 4 percent year-on-year.

"China is the biggest country for smartphone sales, representing 30 percent of total sales of smartphones in the second quarter of 2015. Its poor performance negatively affected the performance of the mobile phone market in the second quarter," said Gartner analyst Anshul Gupta.

This could pose a challenge for manufacturers, predicted Gupta:

"China has reached saturation - its phone market is essentially driven by replacement, with fewer first-time buyers. Beyond the lower-end phone segment, the appeal of premium smartphones will be key for vendors to attract upgrades and to maintain or grow their market share in China."

South Korean powerhouse Samsung remained the go-to choice for many users, holding a 21.9-percent market share. However, the company is losing ground, with overall handset sales down by five percent to 72 million units.

A piece of Samsung's pie appears to have gone to US tech titan Apple, which boosted its market share to 14.6 percent, as iPhone sales shot up to 48 million units.

Three Chinese makers rounded out the top five, Gartner found: Huawei at 7.8 percent, Lenovo at 5.0 percent and Xiaomi at 4.9 percent.

pad/uhe (AP, AFP)