Existing centres of vocational excellence, higher education institutes or independent training companies could be developed into the industry-led vocational colleges, according to the prospectus for sponsors.
The four investors needed by September will have to set up the academies in just 10 months to meet the Government's schedule. By 2008, there should be 12 operational.
Natfhe, the lecturers' union, said FE colleges were being asked to rescue the Government's ill-considered plans. Barry Lovejoy, head of further education at the union, said: "It seems that the idea of Skills Academies has changed significantly since its origination, perhaps because there are so few private sponsors willing to put up the resources.
"I am pleased to see it is now accepted that a well-resourced further education college can provide the quality training envisaged for the role of academies. Given this, one wonders what was the purpose of promoting privatised alternatives. This has clearly not been thought through adequately."
Skills academies were originally intended to follow the model of the Fashion Retail Academy, which is due to open next month.
The dedicated training centre, sponsored by the billionaire Philip Green, will be based in its own pound;20 million building in central London.
However, the buildings will not be ready until January and students will work from the London College of Fashion, a partner in the academy, for their first term.
The Government is also hoping that remaining skills academies will be cheaper, with a typical cost of pound;10m, half of which would come from sponsors.
Julian Gravatt, director of funding and development at the Association of Colleges, said using FE colleges offered several advantages, including a lower cost and an established, trusted management team.
Many would want to become involved, he said, but some would question whether inflexible, single-industry centres were the best way of spending money on vocational training.