was a subsidiary of
American Telephone & Telegraph serving the state of
Michigan . Following the
Bell System Divestiture on
January 8 ,
1982 , the company became a subsidiary of
Ameritech , the
Regional Bell Operating Company that served the
Midwestern United States . Ameritech was subsequently acquired by
SBC Communications , which later changed its name to
AT&T .
Michigan Bell was one of the 22
Local Exchange Carrier s that were part of the original
AT&T Bell System until the
1984 Divestiture , after which Michigan Bell and four other Midwestern telephone companies became part of
Ameritech , the midwestern
Regional Holding Company . Ameritech was one of the 7 original Bell Regional Holding Companies, or "Baby Bells." By the early 90's Ameritech phased out state specific names such as Michigan Bell in favor of using the Ameritech name for marketing purposes. After Ameritech's acquisition by SBC Communications, the former Ameritech companies were briefly marketed as SBC Ameritech, as transition to a unified "SBC" brand name in all 13 states in which SBC then did business. No sooner had this been accomplished then, in
2005 , SBC Communications acquired AT&T. The newly merged company began marketing itself throughout the United States as the "new"
AT&T . Michigan Bell is stil the legal entity that provides telecommunications services in Michigan under the AT&T name. It is headquartered in Detroit.
