Transport for London (TfL) has this week launched its search for an operator to run Crossrail train services from May 2015.
Operators have until the end of April to submit their interest and will be based on the system used for London Overground.
The winning bidder will have responsibility for running services and many stations along the route between Maidenhead in the west and Shenfield and Abbey Wood in the east.
“We are now starting the procurement process to find a truly first rate operator to run the Crossrail services,” said London Rail chief operating office Howard Smith.
Services for Crossrail will begin between Liverpool Street and Shenfield from May 2015 replacing the existing Greater Anglia stopping service. Services under central London will begin in December 2018 with full route operational from December 2019.
The operator is due to be appointed by late 2014.