telephone company (TELCO)
TELCO stands for Telecommunication Company and is a generic term for telephone companies that offer their services regionally, nationally, internationally or globally. Typical examples of telcos are the Regional Bell Operating Companies( RBOC), Local Exchange Carriers( LEC), Interexchange Carriers( IXC) and Postal, Telegraph and Telephone( PTT).
The term telco was previously used only in the USA, but is now used internationally.