An injunction request filed by America Movil against new rules designed to curb its dominance in Mexico is being examined by a court, according to Reuters.

America Movil was ruled to be dominant by the newly created Federal Telecommunications Institute (IFT) in March due to its 70 per cent share of the Mexican mobile market, and 80 per cent share of the fixed-line market.

Earlier this month the IFT announced tougher rules for the fixed and mobile operations of America Movil as part of an effort to improve competitiveness in the market. These cover roaming, unlocked phones and billing.

The court specialising in competition and telecoms cases said it had admitted the injunction against the IFT, with a Federal Judicial Council hearing set for 13 May to hear arguments from America Movil and the IFT.

The IFT required America Movil’s mobile unit Telcel to stop charging customers more expensive roaming charges when calls are made within Mexico. Roaming charges for incoming calls were also scrapped.

In addition, Telcel customers who pay for their mobile phones in full – either as part of a contract or pre-paid package – should receive unlocked devices.

On billing, Telcel was ordered to separate charges made for telecoms and non-telecoms services. In this way, users who keep up to date with their telecoms payments will not have their mobile service cut off if they fall behind on other payments.

Telefonica, which is the second-largest mobile operator in Mexico, said on Monday that it felt America Movil was failing to follow the rules it had been set, according to Reuters.

The measures by IFT are part of a crackdown on anti-competitive behaviour by President Enrique Pena Nieto.