Mexico's lower house of Congress gave general approval Thursday night to a plan to overhaul the telecommunications sector that seeks to loosen Carlos Slim's hold on the phone business and broadcaster Televisa's dominance of the airwaves.

The bill attracted overwhelming support, with 414 lawmakers in favor of the reform and only 50 opposed.

Lawmakers must still vote on amendments to the bill, which has dampened confidence in Slim's prospects, though investors are hopeful the Mexican tycoon can at least partly offset curbs to his phone empire by entering the television market.

(Reporting by David Alire Garcia; editing by Jackie Frank)