Mexican media giant Televisa has agreed to acquire a 50 percent stake in the Iusacell mobile phone company for 1.6 billion dollars, the company said Thursday."Televisa will invest 37.5 million dollars in capital and 1.565 billion dollars in Iusacell convertible debt. Once the debt has been converted, Televisa's share in Iusacell will be 50 percent," it said.Iusacell, the third largest mobile telephone company in Mexico, is owned by Ricardo Salinas Pliego, owner of Azteca TV, the second largest broadcast television network in Mexico.