The Association of Greater Manchester Authorities has given the green light to three Metrolink extensions, running to Oldham and Rochdale town centres and to Manchester Airport via Wythenshawe.
At an AGMA meeting on Friday, the leaders of the city region's ten local authorities confirmed funding of £500m from the Greater Manchester Transport Fund to deliver the three new tram lines.
The announcement means Metrolink trams will be running to Oldham and Rochdale town centres by spring 2014 and to Manchester Airport by mid 2016.
Lord Peter Smith, chair of the AGMA executive, said: "Public transport has a crucial part to play in supporting Greater Manchester's economy and these Metrolink extensions will give a huge boost to the region. I am delighted that these vital projects can now go ahead.
"The major transport schemes covered by the Greater Manchester Transport Fund have been prioritised based on their value to the regional economy.
"They have been identified as schemes that will support economic recovery and future growth by both creating jobs and improving access to jobs, education, leisure and healthcare.
"If delivered in full, the investment programme is forecast to increase total employment in Greater Manchester by 21,000 by 2021 above what it would otherwise have been. Overall, the potential programme is forecast to be worth £1.3bn per year by 2021.
"These new Metrolink lines in particular will also be the catalyst for regeneration in several areas, so today's announcement is great news."
Cllr Ian Macdonald, chair of Greater Manchester Integrated Transport Authority, added: "This further expansion of the Metrolink network will be a real boost both to the local areas as well as Greater Manchester as a whole, supporting the future growth of the regional economy, taking car journeys off the roads and vastly improving public transport links."
Manchester Airports Group has also agreed to provide a contribution to funding for the Airport line.
Geoff Muirhead, chief executive of the Manchester Airports Group, said: "We are delighted at this news, and have been long standing supporters of the Metrolink extension since it was first proposed.
"We have consistently maintained that support and are pleased to see it coming to fruition, as it will make us one of the most accessible destinations in the region.
"We have already invested over £100m in the airport station and millions of passengers already use our extensive bus, coach and rail routes to get their flights to our 190 destinations worldwide.
"Metrolink is a crucial addition to our services and will extend our reach into the conurbation of Greater Manchester."
In addition to the 48 new trams currently on order for Greater Manchester's expanding Metrolink network, 14 new trams will be ordered to serve the extensions to Manchester Airport and Oldham and Rochdale town centres. This will bring the total number of new trams for Manchester's expanded Metrolink to 62.