[citation needed] In 1950, the same investors bought the Mexican branch of the ITT Corporation, thus becoming the only telephone provider in the country.

[citation needed] In 1990, Telmex was bought by a group of investors formed principally by Carlos Slim Helú, France Télécom, and Southwestern Bell Corporation, whose tender was the largest.

[clarification needed] After privatization, Telmex began investing in new modern infrastructure, creating a partial fiber optic network throughout the nation, thus offering service to 30% of the Mexican territory.

[citation needed] In the 1990s, Telmex formed a subsidiary Radio Móvil Dipsa to provide mobile communications under the brand Telcel.

In August 2012, America Móvil started the process to de-list Telmex from the Mexican Stock Exchange.

[citation needed] As of 2005[update], Telmex holds more than 80% of the market as an ISP, and is also the leader in broadband access with its brand Prodigy Infinitum (ADSL).

[citation needed] In the mid-1990s, AT&T Corporation and WorldCom (MCI), among others, began operating in Mexico, representing for the first time serious competition to Telmex.

[citation needed] In 2004, Telmex went into a shopping spree for undervalued operators in South America, including the purchase of AT&T's Latin American operations, giving it presence in Colombia, Venezuela, Peru, Paraguay, Chile, Argentina, Brazil, and Uruguay, and increased reach in the United States.

[citation needed] In November 2006, an American embassy cable listed Telmex as among "Mexico's monopolists", with a 95% share of landlines.

[citation needed] In January 2007, Telmex launched Prodigy Media, the first step to offer triple play services to the Mexican market.

Days later, Telmex started the first Wi-Max network in Chile, offering local, long-distance and Internet services to 98% of the Chilean population.

Currently, the company operates in more than 50 cities in Colombia including Bogota, Cucuta, Bucaramanga, Ibague and Neiva, among others.

The acquisition was approved by the CFC (Comisión Federal de Competencia) Antitrust Office in Mexico on February 11, 2010.