ITV plc is a British media company that holds 13 of the 15 regional television licences that make up the ITV network, the oldest and largest commercial terrestrial television network in the United Kingdom. The network, which is branded ITV by ITV plc, has vied with the British Broadcasting Corporation's BBC One for the status of the UK's most watched channel since the 1950s (a crown it lost in 2005). ITV plc is listed on the London Stock Exchange and is a constituent of the FTSE 100 Index.