Mexico's Federal Competition Commission said on Friday it has started separate investigations into alleged monopolistic practices in the sale of television advertising and telecommunications interconnection services.
Neither announcement named any companies directly, but the two investigations are the result of complaints filed with the authority.
A bitter feud between telecommunications tycoon Carlos Slim and television baron Emilio Azcarraga has dominated the Mexican business scene in recent months.
Mexico's telecommunications sector is led by Slim's America Movil, which controls the top mobile and fixed-line telecommunications firms. Azcarraga's Televisa is the country's largest broadcaster.
The rivalry between the two tycoons has deepened in the last year as both have sought to enter the other's markets, upsetting the cozy order of Mexico's business elite.
Slim wants to offer cable television along with his phone services while Azcarraga is pushing into telephone services through his cable company Cablevision.
Slim's companies yanked their advertising from Televisa after ad rates jumped 20 percent in February and both sides have been trading public accusations of anti-competitive behavior, poor service and market manipulation, often through front page newspaper advertisements.
America Movil was slapped with a nearly $1 billion fine by the competition authorities earlier this month for allegedly abusing its dominant position in mobile telecommunications. The company denies it abuses its market power and has said it will appeal the ruling.
(Reporting by Robert Campbell and Veronica Gomez, editing by Gerald E. McCormick and Derek Caney)