Mexican billionaire Carlos Slim is buying back the stake AT&T owns in his company, America Movil. Since agreeing to acquire satellite provider DirectTV, the telecom company has become a competitor of America Movil for paid TV customers in Latin America. AT&T has been gradually reducing its holdings in America Movil in the past few years. In 2013, AT&T sold over 1.5 million shares. When the transaction is completed, AT&T and America Movil will end their partnership that lasted for more than 20 years. This transaction also makes AT&T's bid for DirectTV more likely to be approved by U.S. antitrust regulators. With DirectTV, AT&T hopes take on other major cable TV providers. It will create a strong rival to Comcast, who itself wants to takeover Time Warner Cable. Currently, DirectTV is the second largest satellite provider in the U.S. with 20 million customers. It also has more than 18 million customers in Latin America. TheStreet's Julia Sun reports from New York.