TfL shortlists companies to operate London Overground services June 29, 2015 | Europe News Transport for London (TfL) has shortlisted four train operators, including Arriva Rail, LoKeGo (a joint venture of Keolis and Go-Ahead), Metroline and MTR, to operate the London Overground services... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password