Mexico City, Mexico - Earlier this month, Mexican regulators made progress on a plan to redefine area codes so that phone carriers such as America Movil SAB (AMXL) have to charge local prices instead of heftier long-distance fees.

The decision would cut the number of area codes to 172 from 397, the Federal Telecommunications Commission said in a statement. The agency altered and resubmitted the plan to the Federal Commission for Regulatory Improvement, which must sign off on it before it can become official.

Mexican officials have been seeking to reduce area codes for several years, meeting opposition from America Movil, which said previous plans were designed to favor its competitors. The phone agency is running out of time to implement the plan because it is due to be replaced by a new government body under a law signed this month by President Enrique Peña Nieto.

Long-distance minutes by America Movil’s landline phone customers jumped 21 percent last year from 2011 even as total lines fell 4 percent. That was partly because government-mandated reductions in other types of fees made it cheaper to make phone calls.

A press official at Mexico City-based America Movil, which has about 80 percent of Mexico’s landlines and 70 percent of mobile phone subscriptions, declined to comment.