The
Regional Bell Operating Companies (
RBOC) are the result of
United States v. AT&T, the
U.S. Department of Justice antitrust suit against the former American Telephone & Telegraph Company (later known as AT&T Corp.). On January 8, 1982, AT&T Corp. settled the suit and agreed to divest its local exchange service operating companies. Effective January 1, 1984, AT&T Corp.'s local operations were split into seven independent
Regional Bell Operating Companies known as "
Baby Bells". RBOCs were originally known as
Regional Holding Companies (RHCs). Currently, three companies have the RBOCs as predecessors. They are
AT&T Inc.,
Verizon, and
CenturyLink. Some other companies are holding on smaller segments of the companies.