Device vendors TCL and Asus have plans to sharply expand their smartphone shipments this year as they face increased competition from low-cost makers in China and India.

China-based TCL plans to boost shipments of smartphones to 70 million units from 40 million last year. The devices will run on multiple platforms, including Android, Firefox OS and Windows Phone.

The company, which sells handsets under the Alcatel OneTouch brand, shipped about 65 million handsets in 2014 and expects total mobile phone sales to reach 100 million this year.

Meanwhile, Asus said it shipped eight million smartphones last year and aims to double that in 2015. The firm is mainly targeting the $129-257 segment and exports to 15 countries, with China and North America its key markets, DigiTimes said.

The Taiwanese device vendor strengthened its portfolio this week with the launch at CES of a new version of its Zenfone smartphone.

Last week fasting-growing rival Xiaomi announced its smartphone sales jumped 227 per cent to 61 million units in 2014, while Huawei said smartphone shipments increased 40 per cent to 75 million.

Global smartphone sales growth slowed to 20 per cent in the third quarter, according to Gartner. Smartphones now account for about 65 per cent of total handset sales.