At Willesden Junction station in north London, Livingstone said, "London Overground, giving Transport for London control of key parts of the overground rail services in the capital, is the start of a radical revitalisation of London’s rail services, which have suffered from decades of neglect and under-investment.
"Our aim is very simple, to raise standards to levels similar to the rest of the public transport system in London, with Oyster ticketing and stations staffed at all times while trains are running.
"Over the next few years huge investment will bring more secure stations, new trains and a more frequent and reliable service.
"The new rail system will create 400 jobs over the next three years and with its connection to the East London line, radically improve public transport provision in some of the poorest boroughs in London," he said.
Transport Commissioner Peter Hendy said, "When complete, with the renewal and extension of the East London line due in 2010, the London Overground network will also play a key role in our transport for the London 2012 Olympics."
Jo Valentine, Chief Executive of business group London First said, "This is a much needed fresh start for London's forgotten railways, particularly the long-neglected former North London line, with a new operator and a new champion in the Mayor.
"Investment in London's transport systems is good news for commuters and good news for employers.
"Demand for commuter journeys is projected to rise by 40% by 2025. An orbital railway for London will help meet that growth and will help to drive - alongside Crossrail - the regeneration of East London.
"Additional funding will have to be identified if the potential is to be fully realised, to complete the second phase of the East London line," she said.
The London Overground network links North London (Richmond to Stratford), West London (Willesden Junction to Clapham Junction via Kensington Olympia), Gospel Oak to Barking and Euston to Watford DC lines, and will be joined by the extended East London line when it opens in 2010 and will link with the North London line at Highbury & Islington in 2011.
Transport for London’s Managing Director of London Rail, Ian Brown will manage the £1.4bn upgrade. London Overground Rail Operations Ltd, a joint venture of MTR and LaingRail, will operate trains and stations under the new London Overground concession. MTR runs the Hong Kong Metro and Laing operates Chiltern Railways.