[5] In June 2007, Transport for London awarded the concession to MTR Laing, and operations started on 11 November 2007.

[8] In December 2007, Henderson Group, the parent company of John Laing plc, announced the sale of the Laing Rail division, which comprised half of LOROL, Chiltern Railways and a stake in the Wrexham & Shropshire open-access railway operator.

[10] Laing Rail became part of DB Regio, before a restructuring saw it moved under the control of Arriva UK Trains.

In April 2015, Transport for London placed a notice in the Official Journal of the European Union, inviting expressions of interest in operating the next concession.

[12] In July 2015, Transport for London announced the shortlisted bidders for the next concession were Arriva UK Trains, ComfortDelGro, a Keolis/Go-Ahead joint venture and MTR Corporation.