AT&T Inc. (sometimes stylized as at&t ; for "telephone") is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services. AT&T is the 7th largest company in the United States by total revenue, as well as the 4th largest non-oil company in the US (behind Walmart, General Electric and Bank of America). It is the 3rd largest company in Texas by total revenue (behind ExxonMobil and ConocoPhillips) and the largest non-oil company in Texas. It is also the largest company headquartered in Dallas. In 2011, Forbes listed AT&T as the 14th largest company in the world by market value and the 9th largest non-oil company in the world by market value. It is the 21st largest mobile telecom operator in the world with over 100.7 million mobile customers.
The company began its existence as Southwestern Bell Corporation , one of seven Regional Bell Operating Companies created in 1983 as part of the break-up of the original AT&T due to the United States v. AT&T antitrust lawsuit. It changed its name to SBC Communications Inc. in 1995. In 2005, it purchased its former parent company, AT&T Corporation, and took on its branding, with the merged entity naming itself AT&T Inc. and using the iconic AT&T logo and stock-trading symbol.
The current AT&T reconstitutes much of the former Bell System and includes ten of the original 22 Bell Operating Companies along with one it partially owned (Southern New England Telephone), and the original long distance division. The company is headquartered in downtown Dallas, Texas.