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.

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 broadcasting giant Televisa.

(Reporting by Gabriel Stargardter; Editing by Ken Wills)