Telenor had offered customers zero-tariff packages in which certain applications were deducted from the consumption tally.

A Hungarian court had sought guidance from the Luxembourg court on the issue that goes to the heart of whether telecom firms should abide by the principle of net neutrality.

Blocking or slowing down traffic for certain types of application is seen as a violation of that principle.

Hungary’s media and telecoms watchdog (NMHH) argued in its suit that Telenor’s package breached the net neutrality regulation that ISPs may not discriminate between the internet content they make available.

The EU Court of Justice on Tuesday interpreted the regulation in question for the first time.

MTI Photo: Balázs Mohai