The European Commission (EC) opened an investigation into the network sharing agreement between O2 and T-Mobile in the Czech Republic, to ensure it is not in breach of antritust laws.

The EC wants to see if the agreement “risks slowing down quality improvements in existing infrastructure, and delaying or hindering the deployment of new technologies, such as 4G/LTE, and new services based on them, in particular in densely populated areas”.

The Commission will also look into the potential efficiencies which could be brought about by network sharing.

EU Commissioner in charge of competition policy, Margrethe Vestager, said: “The network sharing agreement between the two major operators in the Czech Republic covers most of the country. We need to ensure that it will not reduce infrastructure competition and innovation.”

O2 CZ and T-Mobile CZ serve three quarters of the Czech retail mobile market. O2’s mobile infrastructure and wholesale business has been transferred to CETIN, a new network infrastructure company belonging to the same corporate group.

The network sharing deal started in 2011 and has been increasing in scope. Currently it covers the entire territory of the Czech Republic with the exception of the cities of Prague and Brno – around 85 per cent of the country’s population.

T-Mobile is the top operator in the country with a 42.6 per cent market share, followed by O2 (32.1 per cent), Vodafone (24 per cent) and U:fon (1 per cent), according to GSMA Intelligence.

The EC wants to examine the case as a matter of priority, but said it “does not prejudge the outcome of the investigation”.