SAN FRANCISCO - Chinese telecom companies Huawei Technologies Co Ltd and Xiaomi Inc are among the top five global vendors of smartphones that recorded growth in smartphone sales in the fourth quarter of 2017, the world leading market research firm Gartner said on Thursday.

Moreover, Huawei and Xiaomi were the only smartphone vendors to have achieved year-on-year unit growth, which was 7.6 percent and 79 percent, respectively, Gartner said in a report.

Global sales of smartphones to end users totaled nearly 408 million units in the fourth quarter of 2017, a 5.6 percent decline over the same period of the previous year, the report showed.

The drop in the worldwide sales of smartphones is the first year-on-year decline since Gartner started tracking the global smartphone market in 2004.

The two Chinese companies grew their market shares in the fourth quarter of 2017, as Huawei added new smartphone models including Mate 10 Lite, Honor 6C Pro and Enjoy 7S that broadened the appeal of its mobile products.

Xiaomi's competitive smartphone portfolio consists of its Mi and Redmi models, which helped accelerate its growth in the emerging Asia-Pacific (APAC) market, as well as its regained hold in the domestic market shares back in China.

"Future growth opportunities for Huawei will reside in winning market share in emerging APAC and the US," said Anshul Gupta, research director at Gartner.

Smartphones sales to end users in 2017 totaled over 1.5 billion units, an increase of 2.7 percent from 2016, and Huawei, ranked No 3, raised its share in 2017 by continuing to gain on Apple, the tech giant in the United States.

Huawei sold about 150.534 million units of smartphones last year, accounting for 9.8 percent of the world total.

Xiaomi sold 28.188 million units of smartphones in the fourth quarter of last year, making up for 6.9 percent of the global market shares.

The combined market share of the Chinese vendors in the top five increased by 4.2 percentage points, while the market share of top two, Samsung and Apple, remained unchanged.

"Xiaomi's biggest market outside China is India, where it will continue to see high growth. Increasing sales in Indonesia and other markets in emerging APAC will position Xiaomi as a strong global brand," Gupta said.

Xiaomi, headquartered in Beijing, capital of China, is a Chinese electronics and software company that designs and sells smartphones, mobile apps, laptops and consumer electronics.

Huawei, founded in 1987, is also a Chinese multinational networking and telecom equipment and services company based in Shenzhen, southern China. It is the largest telecom equipment manufacturer in the world.