By Jeremy Wagstaff

SINGAPORE, Nov 18 (Reuters) - China Mobile International, a unit of China Mobile, has launched an application it hopes will win business from millions of overseas Chinese and others communicating with China.

The app, Jego, allows anyone outside China with an Android or iOS smartphone and a data connection to receive free incoming calls on a China Mobile number, if they have one, or via a rented number if they don't. They can also make cheap international calls using the app.

China Mobile, with more than 700 million subscribers, is the world's largest mobile operator and the most profitable, according to ABI Research. But it has struggled to gain a foothold overseas, with only one carrier to its name, it's Pakistan unit Zong.

Operators globally have been hard hit by the rise of social messaging apps that offer voice, messaging and other services over 3G data connections. Asian services like TenCent's WeChat, LINE and KakaoTalk have been particularly successful.

Microsoft's Skype also offers voice over Internet, or VoIP, services where users can communicate for free, or call traditional telephones at cheaper rates.

Tiger Lin, CEO and chairman of Hong Kong-based China Mobile International, said in an interview the new service would later target China's domestic market and non-Chinese markets through partnerships with other operators using its network.

"This service is really providing traditional services over a new technology," he said. He denied that the service might cannibalize existing revenues of China Mobile.

China Mobile International, or CMI, is China Mobile's wholly owned subsidiary responsible for international business.

CTO John Jiang said Jego will save roaming users money, allow them to communicate as if they were in China, and also provide a way for them to send text messages, share pictures and make voice and video calls for free.

"We are essentially combining a mobile number with Internet technology," Jiang said.

He denied the move was a response to the rise of apps like WeChat, but leveraged China Mobile's international network to "internetize" communications by binding a mobile number to an app rather than a SIM card.

The company released a version of Jego in June but quickly withdrew it, Jiang said, because it was a prototype and demand had overwhelmed the network.