A UK agency licensed to provide data transmission services to organizations or private individuals, where the services cross public rights of way. Within the UK, until the mid-1980s, the only organization able to offer such services was British Telecom (previously the GPO) and, for purely historical reasons, the civic authorities in the city of Hull. At the time of the BT privatization, legislation was enacted that allowed the creation of further PTOs, although for a long time only Mercury took advantage of this. There are now a large number of organizations taking out licenses to act as PTOs, driven in part by the installation of optical fibre networks in metropolitan areas. See also public network operator.