Mexico's telecommunications regulator has postponed a deadline for potential bidders to apply to take part in an auction of two new nationwide television networks.

The decision "offers greater certainty to interested parties and promotes the maximum participation in this bidding process," the IFT said in a statement.

The deadline for potential participants to obtain anti-trust clearance had been June 16-17 but it is now set for Sept. 2-3.

The rules for the auction, aimed at weakening the duopoly of No. 1 Mexican broadcaster Televisa and rival incumbent TV Azteca and fulfilling one of the main goals of last year's telecommunications and broadcast TV overhaul, were unveiled in March.

The IFT said the deadline needed to be postponed to bolster legal certainty since the overhaul's secondary laws have not yet been approved.

The auction will be the first of television frequencies in Mexico's history.

The auction of the 20-year concessions is aimed, among other things, at diversifying content.

In March, Mexico City-based Televisa said in a statement that the IFT had declared it a dominant operator in broadcast television and published an invitation to a public option in which companies - not including Televisa and TV Azteca - may bid to obtain frequencies to set up at least two additional national digital broadcasting networks in Mexico.

Televisa said that under the tighter regulatory regime it also will have to "make its broadcasting infrastructure available to third parties on a non-discriminatory and non-exclusive basis."

Carlos Slim-controlled America Movil was likewise declared by the IFT as a "preponderant economic agent" in the telecommunications sector. EFE