While Apple Inc's iPhone uses its own iOS software, most other smartphones sold around the world are powered by Android. Firefox OS is an open-source, Web-based operating system. "We have huge confidence in the Firefox OS platform and expect to deliver more than one million Firefox OS phones this year alone," Kan said.

ZTE said users will find the operating system "fresh" and simple to use. It comes with "a full range" of features and apps, including camera, dialer, text messaging and games. "Web apps are not resource intensive, so users can enjoy higher performance at a more affordable price," ZTE said.

The Open II evolves from the ZTE Open, launched last year at the Mobile World Congress with the help of Telefónica in Spain, Venezuela, Colombia, Peru, Mexico and Uruguay. The phone later was sold in the US and UK via eBay, initially selling out in just three days. In addition to eBay, ZTE said it will also cooperate with additional e-commerce platforms for both the Open C and Open II.

Li Gong, Mozilla's senior vice-president of mobile devices and president of its Asia operations, said ZTE was one of Mozilla's first partners to launch a Firefox OS phone, the ZTE Open. "We have worked closely together to continue advancing the new platform. The ZTE Open C and Open II are the latest examples of how Firefox OS has evolved to bring powerful open Web technologies to the smartphone," Li said.

ZTE's embrace of Mozilla's new mobile operating system comes as the technology industry closely watches Apple's patent war against rival smartphone makers using the Google software. Though Android's global market share on smartphones is far larger than the iOS's, Apple's operating system still defines the smartphone standard.