A number of internet service providers are in the sights of European Union competition regulators.
The European Commission is carrying out so-called “unannounced inspections” at the head offices of France’s Orange, Germany’s Deutsche Telekom, and Telefonica of Spain searching for evidence.
The raids – which started on Tuesday – are based on suspicion that the telecoms giants may have abused their dominant position in the sector.
Orange said it was cooperating fully and did not believe it had done anything incriminating.
Sources said the investigation was focused just on three telecoms companies. KPN of The Netherlands and the Belgian firm Belgacom said they were not raided.
Brussels stressed the probe did not mean the companies were guilty of anti-competitive behaviour, but if that turns out to be the case they can be fined as much as 10 percent of their global turnover.