P&O Scottish Ferries was a ferry company which operated ferry services between the Scottish mainland and the Orkney and Shetland Islands from 1971 to 2002. P&O took over the routes from the long-established North of Scotland, Orkney & Shetland Steam Navigation Company in 1971. They originally branded their services as P&O Ferries from 1975 to 1989 and P&O Scottish Ferries thereafter. Being a subsidised service the route was put out to tender in 1999 with the tender being awarded to a joint venture between Caledonian MacBrayne and RBS Group, named NorthLink. Today the service is operated by the Serco Group trading as Northlink Ferries.