Ameritech

Ameritech

AT&T Teleholdings, Inc., formerly known as Ameritech Corporation (and before that American Information Technologies Corporation), was a U.S. telecommunications company that arose out of the 1984 AT&T divestiture. Ameritech was one of the seven Regional Bell Operating Companies that was created following the breakup of the Bell System. Ameritech was acquired by SBC Communications in 1999 which subsequently acquired AT&T Corporation in 2006, becoming the present-day AT&T Inc.

Ameritech was created as a holding company; under its umbrella were:

• Illinois Bell Telephone Company
• Indiana Bell Telephone Company, Inc.
• Michigan Bell Telephone Company
• Ohio Bell Telephone Company
• Wisconsin Bell, Inc.

For Ameritech's first nine years, it maintained these Bell brands inherited from the Bell System—though public displays of the Bell companies' names were often captioned "An Ameritech Company". In January 1993, Ameritech officially retired the Bell brands and marketed itself with solely the Ameritech name across all five states in its territory. It added "d/b/a Ameritech (state)" to the names of its Bells to communicate brand unity.

Ameritech also owned Ameritech Cellular, a wireless company that operated cellular networks in many of the major cities of these states. Ameritech Cellular was previously called Ameritech Mobile Communications.

Prior to its merger with SBC Communications, Ameritech's corporate headquarters were in a leased space above the Chicago Mercantile Exchange on floors 34 through 39 of 30 S Wacker Dr, Chicago IL. Further corporate offices were located at 225 W Randolph St, Chicago IL (formerly "The Illinois Bell Building") and 2000 W. Ameritech Center Drive, Hoffman Estates, IL ("The Ameritech Center"). It was traded on the NYSE under the "AIT" symbol.