(Adds fall of Televisa share price, reform background)
MEXICO CITY, March 13 (Reuters) - Shares of Mexican billionaire Carlos Slim's America Movil telecoms company fell 2.26 percent on Wednesday, continuing a slide since a plan for a major overhaul of the phone and television market was unveiled on Monday.
The sweeping reform bill presented by President Enrique Pena Nieto aims to end Slim's stranglehold on the phone business and broadcaster Televisa's dominance of the airwaves.
It foresees allowing more foreign ownership of media and phone companies, and giving regulators the power to make players controlling more than 50 percent of the market sell assets.
America Movil shares dipped to 12.54 pesos after trading began. The slide took America Movil's stock to its lowest level since July 8, 2009.
Year to date, the company's stock has lost more than 16 percent of its value.
Televisa shares fell 1.05 percent, dipping below 67 pesos shortly after trading started.
Slim, the world's richest man, dominates Mexico's telecommunications market, controlling about 70 percent of its mobile market and 80 percent of its fixed phone lines.
Televisa, the world's largest Spanish-language content producer, is reckoned to control about 60 percent of Mexico's broadcast market.
Previous Mexican governments have failed to rein in the power of the huge telecommunications companies and the reform bill still faces a number of hurdles before it can become law. (Reporting by David Alire Garcia; Editing by Maureen Bavdek)