Hrvatski Telekom (T-HT) and its sister company Iskon will be required to raise the prices of their internet and IPTV offers from June 1.
According to local reports, this follows a decision of the regulator HAKOM, which argues that the two have significant market power and distort competition.
Significantly, existing subscribers will only see their fees raised following the expiry of their contracts.
Competitors such as Vipnet, H1 Telekom, Metronet and Optima Telekom have welcomed the controversial move.