Transport for London (TfL) is to take over the running of some mainline rail services and stations.
TfL will be responsible for some West Anglia routes from Liverpool Street station to Enfield Town and Chingford, in north London, and Cheshunt.
The route includes 25 stations, with TfL taking over 23 of them, from around 2015.
Liverpool Street and Chingford stations will remain the responsibility of Network Rail or Greater Anglia.
TfL, which already runs mainline London Overground services, said changes will include improved reliability, security and better passenger information.
But plans to takeover Southeastern services are "unlikely to happen at the present time", TfL has said.
London Mayor Boris Johnson said: "You only have to look at the success of London Overground to see how TfL taking over this commuter service will transform the journey for passengers.
"It will also open up the north-east of London and drive jobs and growth in Tottenham and beyond."