From November 2007, London Overground train services will operate on the North London Railway under the management of Transport for London (TfL), when it assumes responsibility for the line from the Department for Transport.
Operating under a new TfL London Rail Concession, London Overground services will also run on the East London Railway when it opens in 2010, following TfL's £1bn extension of the existing East London Line.
The contract to run London Overground services on both these lines will be awarded by TfL to a single train operator, under strict conditions to meet TfL's requirements for safety, security, staffing, ticketing and train frequency.
Launching his vision for the London Overground, the Mayor Ken Livingstone said:'For decades, national rail services in London have been neglected and in many cases under-utilised.
'The transfer of responsibilities to Transport for London and the dawn of 'London Overground' will start the much needed revitalisation of London rail services, bringing the standards of service up to the levels of the Tube and the buses.'
The Mayor signalled his commitment to deliver a rail link at Dalston Junction to connect the North and East London Railways by 2010, ahead of the London 2012 Olympics.
This will allow London Overground passengers to travel between Richmond and West Croydon via Dalston Junction and is the first step towards an orbital rail link for London.
The Mayor continued: 'By joining together the North and East London Railways ahead of the London 2012 Olympics, we will create a new rail artery around the city, serving 20 London boroughs.
'This will create new opportunities for Londoners and encourage inclusion across our diverse economic and cultural centres.
'It will also be a vital means of increasing capacity on public transport as London's population grows over the next twenty years.'
From November 2007, London Overground passengers will benefit from a programme of improvements to stations and services on the North London Railway, funded by TfL's £10bn Investment Programme.
Ian Brown, Managing Director, TfL London Rail added: 'TfL's policy is to put passengers first and we look forward to putting this into practice on London's rail network from November next year.
'Over the next few years we hope to develop the London Overground to its full potential, using TfL's values to raise security and standards for rail passengers, as we have for other transport modes in London.
'TfL's vision for the London Overground is a safe and secure railway with frequent, Metro-style train services. Passengers will benefit from a better quality of service with new, reliable trains, staffed stations and Oyster ticketing to ensure consistent fares.
'We want the London Overground to be as comfortable and familiar to Londoners and visitors to the capital as the London Underground. We're entering a new era for London Rail and this is just the beginning.'
The London Overground brand will join the TfL family as a new orange roundel, featuring on trains, stations and maps, including TfL's world-famous Tube map.