United Group had planned to carry out the transaction via its subsidiary Slovenia Broadband, which is an international holding company that manages various companies in Central and Eastern Europe, including in Croatia, the regulator said in a statement earlier this week.
In July, United Group, backed by US investment firm KKR and the European Bank for Reconstruction and Development (EBRD), said it had agreed to acquire the Croatian and Slovenian media portfolio of Central European Media Enterprises (CME), including broadcaster Nova TV.
Croatia's regulator for electronic media has found issued with the acquisition because United Group also runs Total TV in Croatia.
The regulator explained that its decision aimed to protect pluralism and the diversity of electronic media.
CME is a media and entertainment company operating leading businesses in six Central and Eastern European markets with an aggregate population of approximately 50 million people. It currently broadcasts 36 television channels in Bulgaria, Croatia, the Czech Republic, Romania, the Slovak Republic and Slovenia.