The move comes after US authorities expressed concern that the firm's ownership of the US-based firm is a national security risk, sources told Reuters news agency.

Kunlun Group bought a 61.5% stake in 2016 from the company's US founders, taking full control in January 2018.

It had been planning a stock market listing for the app.

However, it has apparently changed its mind following the intervention of the Committee on Foreign Investment in the United States, a US government body that reviews the national security implications of foreign investments in US companies or operations.

According to Reuters, investment bank Cowen has been taken on to manage the sale process.

None of the parties involved has made any public comment on the reports.

Grindr, which is based in Los Angeles, is a hugely popular dating network for lesbian, gay, bisexual and transgender people, with more than 27 million users globally.

It is free to use, with optional subscription plans for additional premium features.

Grindr was the first gay social networking app on the iTunes App Store and is currently available in 192 countries, although its user base is primarily located in developed countries in Europe and North America.

The app was founded in March 2009 by Joel Simkhai, an Israeli immigrant to the US who grew up in Mamaroneck, in the state of New York.