Regional Bell Operating Company
（重定向自Baby Bells）
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.