Orange and SFR could face sanctions from the French regulator Arcep after they failed to meet requirements for rolling out 2G.
As part of Arcep's Town Centre Not-Spots programme it launched last summer, the regulator issued Bouygues Telecom, Orange and SFR a demand to deploy 2G in 17, eight and 53 town centres respectively.
While Bouygues Telecom met the 1 January deadline, Arcep found Orange had still to bring 2G to five towns and SFR to 47.
The body responsible for dealing with disputes, legal proceedings and investigations RDPI has forwarded a file to Arcep's "Restricted body", which can impose sanctions.
In a statement, Arcep said: "[RDPI] stressed that the statements of objections pertained to those town centres that had not been covered as of 1 January 2016, and some have been covered since then. It is now up to the Restricted body, following adversary proceedings, to assess the allegations and deliberate over what, if any, sanctions should be imposed on the two operators."
Under the not-spots programme, which is being partly funded by the French government, operators have committed to bringing 2G to at least 3,600 town centres by 31 December 2016 and 3G by 30 June 2017.
Arcep has also placed coverage obligations on its 4G licences, to bring coverage to remote areas. Around 18 percent of France's population lives across 63 percent of its landmass.
Operators with 800MHz spectrum must use it to cover 40 percent of this population by 17 January 2017. While Free Mobile has no 800MHz spectrum, it must cover 50 percent of this population by using 700MHz by 17 January 2022.