Metrobus is a bus operator with routes in south and south-east London, and parts of Surrey, Kent, West and East Sussex. The company operates many routes under contract to Transport for London. Formed through a management buyout in 1983, it was purchased by the Go-Ahead Group in 1999.
Metrobus previously operated many routes under contract to Transport for London in south and south-east London, but following a restructure, on 1 April 2014 these were transferred to Go-Ahead London. The remaining operations were brought under the control of Brighton & Hove on 1 July 2014.
More information on the Wikipedia page [1].