The Korea Fair Trade Commission, South Korea’s antitrust regulator, has fined Google the equivalent of $AUD240 million, after finding the tech giant used its monopoly to restrict competition in the mobile OS sector.

The fine follows another antitrust ruling in South Korea just two weeks ago that banned Apple and Google from restricting app developers from using alternative payment or subscription services within their apps.

The KFTC said Google stifled competition by banning mobile phone manufacturers from installing modified version of the Android OS onto their smartphones.

Google has not commented on the fine.