Televisa is the largest media company in the Spanish-speaking world, followed by TV Azteca, and a major player in the international entertainment business. Grupo Televisa was founded in 1955 as Telesistema Mexicano, linking Mexico's first three television stations: XHTV-TV (founded in 1950), XEW-TV (1951) and XHGC-TV (1952). It was (and in modern-day Televisa still is) owned by the Azcarraga family, who had signed on Mexico's first radio station, XEW-AM, in 1930. Its main headquarters originally was on Avenida Chapultepec, known as Televicentro. This building was started operations on February 10, 1952. In 1968, Televisión Independiente de México (TIM), their main competitor came on the scene with XHTIM, Canal 8. At the same time both Telesistema and TIM were competing with XHAW, local Canal 12, which also started transmissions that year. During the next 4 years both networks were competing in content and image, until September 17 of 1972, both networks finally merged together, bringing the name Televisa with them, in which Telesistema had 75% of the stocks, while Televisión Independiente had the rest, which was sold to Telesistema later because of financial problems. On September 7, 1970, one of the most famous news programs of Mexico was created: 24 Horas. The newsman that was part of that program for 28 years was Jacobo Zabludovsky. On August 17, 1972, Emilio Azcárraga Vidarrueta died and Emilio Azcarraga Milmo became the CEO. Televisa started to transmit several programs produced by Universidad Nacional Autónoma de México (UNAM) in 1977. On March 3, 1983, canal 8 changed their current schedule, to became a cultural profile, with informative programs, debates and cultural shows, a precursor to today's Galavision. In May 18 of 1985 they changed their frequency to XEQ, Canal 9. On September 19, 1985, an earthquake measuring 9.1 on the Richter scale made Mexico City a mess. Televisa's main building had the south tower destroyed in this event, but nothing too serious to compromise their transmissions. In 1991, Televisa, with help from Japanese television network NHK, began its first broadcast in HDTV, using the Japanese MUSE system. In April of 1997, Emilio Azcárraga Milmo died and Emilio Azcárraga Jean became the CEO of the company. In December of 1997, Televisa joined with other Mexican media companies to create a marathon known as Teletón, which mission is to give knowledge about physical discapaties, giving a strong message about respect, equalty and support to persons in this condition. This movement from media, enterprises and Mexicans is reflected with the buildings created with the money of this Marathon, named Centros de Rehabilitación Infantil (CRIT). Grupo Televisa has interests in television production and broadcasting, programming for pay television, international distribution of television programming, direct-to-home satellite services, publishing and publishing distribution, cable television, radio production and broadcasting, professional sports and show business promotions, paging services, feature film production and distribution, dubbing, and the operation of a horizontal Internet portal. Televisa's soap operas generally run only one season each and are broadcast internationally.