Acting to rein in the market power of the nation’s dominant telecommunications and broadcast companies, Mexico’s  Federal Telecommunications Institute (Ifetel) notified wireless carrier America Movil (AM) and broadcaster Televisa they  would be subjected to a raft of newly-adopted rules and conditions that apply to dominant players in the national market.  Handed down last Thursday, the Ifetel ruling corresponds to recent changes in Mexican telecommunications law that cap  the market share of phone service carriers and broadcasters at 50%. Through its holdings in Telmex and Telcel, AM  controls respective shares of 80% and 70% in the Mexican landline and wireless telephony markets. Televisa, meanwhile,  commands a 70% share of the national broadcast television market and a 56% share of Mexico’s combined cable and  satellite television markets. Capping an investigation that was initiated in December, Ifetel concluded that Televisa and  the carriers controlled by AM should be classified as dominant carriers. Under the Ifetel ruling, dominant fixed and  wireless phone carriers will be required, among other things, to (1) share infrastructure, (2) open their networks to virtual  mobile network operators, (3) adopt asymmetric interconnection rates, (4) adhere to certain rules and conditions that  govern local loop unbundling, and (5) eliminate national roaming charges. Dominant broadcasters that include Televisa  will be barred from entering into exclusive content deals and will be also required to share tower space with competitors.  Ifetel (which was established last year as part of the nation’s new telecommunications law) also announced plans to open  bidding later this year for two new national broadcast networks that will compete with Televisa and TV Azteca. While  spokesmen for AM and Televisa confirmed that both companies are reviewing the ruling, one Mexican media analyst  emphasized: “without exaggeration, we are looking at a historic decision.”