(Adds details on so-called secondary laws, Televisa, TV Azteca share prices)
MEXICO CITY, March 25 (Reuters) - Shares in America Movil, the Latin American phone company controlled by Mexican businessman Carlos Slim, fell over 3 percent on Tuesday, the day after the government presented a bill fleshing out a telecoms reform aimed at curbing Slim's power.
Mexico's government on Monday proposed giving a new regulator wide-reaching powers to police the operations of dominant telecommunications companies and TV broadcasters, right down to their prices and discounts.
The bill sent to Congress gives key details on the implementation of the constitutional reform approved last year that seeks to decrease the massive market share enjoyed by mogul Slim and the country's top broadcaster, Televisa.
America Movil shares fell to as low as 13.14 pesos in early trading, while shares in Televisa, which is seen as having a lighter regulatory burden under the new rules, added 0.55 percent.
But shares in TV Azteca, Televisa's smaller broadcasting rival, rose more than 5 percent.
$1 = 13.1933 Mexican Pesos Reporting by Gabriel Stargardter; Editing by Chizu Nomiyama