Orange France has reportedly complained that its new domestic rival, Free Mobile, is taking unfair advantage of a network-sharing agreement between the two operators by diverting a disproportionate amount of traffic onto Orange’s network.

Cellular News claims that, in a letter written to the CEO of Free Mobile by Orange France's VP of wholesale, Brigitte Bourgoin, Orange claims that some 97 percent of phone calls made by Free Mobile's 2 million customers are taking place on its network, creating capacity problems for Orange in some areas.

Orange was obliged to let Free Mobile access its network – allowing it to offer a nationwide service – when the new player achieved at least 27 percent population coverage with its own network. French telecoms regulator Arcep announced that Free Mobile reported in November last year that its 3G network covered more than 27 percent of the population, ahead of its launch last month.

However, recent reports suggest that Free Mobile disabled a number of its base stations once it had secured the network roaming deal with Orange. Arcep is currently investigating the claims.