(Adds details on bidders, background on tender)
MEXICO CITY, Nov 20 (Reuters) - Three companies have presented bids for an upcoming tender to operate two public television networks, Mexico's telecoms regulator said on Thursday, as efforts to open up a sector dominated by broadcasting giant Televisa gather pace.
The three companies are Centro de Informacion Nacional de Estudios Tepeyac, Cadena Tres I and Grupo Radio Centro, the Federal Telecommunications Institute (IFT) said in a statement.
The winners will be chosen by March 19 of next year, the IFT added.
The two new public television networks are the fruit of a sweeping telecoms overhaul, passed last year, that seeks to open up markets controlled by Carlos Slim's America Movil and Televisa.
The IFT said that it had approved proposals from eight interested parties on November 13, but that only three had decided to bid.
Cadena Tres I is part of the Vazquez family empire. The family control the privately owned Grupo Angeles, whose interests include hotels, hospitals and the media company Grupo Imagen, home to one of Mexico's main newspapers, Excelsior.
Estudios Tepeyac is a subsidiary of Organizacion Editorial Mexicana, a newspaper company controlled by another Vazquez family member.
Grupo Radio Centro is run by Mexican businessman Francisco Aguirre.
It had been expected that German Larrea, a reclusive tycoon who controls mining and infrastructure giant Grupo Mexico , would be involved in the tender. Televisa said in September that Larrea had resigned from its board after signaling he wanted to bid on the tender. (Reporting by Gabriel Stargardter and Tomas Sarmiento; Editing by Ken Wills and Stephen Coates)