Three community colleges in West Sussex are to become academies sponsored by a trust which runs 23 private schools.
New buildings are planned for the three sponsored academies
The academies are planned on the sites of Kings Manor Community College, Littlehampton Community School and Boundstone Community College.
They will be sponsored by Woodard Schools, whose private schools include Lancing, Ardingly and Hurstpierpoint Colleges in West Sussex.
West Sussex County Council said £70m would be invested in the new academies.
Woodard said on Tuesday the proposals had been given the thumbs up by the government.
Three "expressions of interest" for the schools in Lancing, Shoreham and Littlehampton, were submitted earlier this year by Woodard and West Sussex County Council.
A "feasibility" phase would now include consultation with parents and the wider community and detailed plans would be prepared.
It was hoped the academies would be formed in 2009, with new buildings in place by 2011.
"This is exciting news and means we can move forward with our ambitious plans to enhance the educational opportunities for young people," said Councillor Mark Dunn.
"The project will see well over £70m invested in these unique schools, which will be redeveloped to provide modern state-of-the-art new facilities."
Woodard runs the largest group of private Church of England schools in England and Wales.
"Woodard Schools has been working closely with the maintained sector for many years," said David Bilton, chairman of its board.
"We believe that in undertaking a feasibility study into the three West Sussex academies we are taking this joint working a step further."