The suppliers and their association are suspected of exchanging sensitive business information to agree on their prices of gas supply for households, thus preventing competition in Slovenia and the EU internal market.

The list of suppliers under close watch includes energy company Petrol, utility Energetika Ljubljana and a number of local utilities.

Andrej Krašek, the head of the agency, which was reformed from the previous Competition Protection Office with the start of the year, had announced in the media recently that the watchdog would take a closer look in the energy market, postal services, food and telecommunications.