The first private prep school sponsor of an academy is expected to be named by the end of the year, with increasing numbers of schools wanting to get involved.
David Hanson, chief executive of the Independent Association of Prep Schools (IAPS), said there was "genuine and heightened interest" from prep schools wanting to back an academy.
"A number of our members have proposals on the table that are being discussed in some detail," said Mr Hanson. "I think that certainly within the next few months we will have an announcement of the first prep school involvement with an academy. There is wide interest in the principle among our schools."
Mr Hanson argues prep schools could make more successful academy partners than senior independent schools because he says they are better at developing basic literacy and maths skills in pupils.
Lord Adonis, the schools minister, has announced plans to expand academies to bring feeder primary schools under the control of the same sponsor and governing body. He has also spoken of his support for all-through academies for pupils aged from 3 to 18.
But Mr Hanson said: "Prep schools don't want to be pigeon-holed in the primary age group. All-age academies are of natural interest, but there is interest in backing secondary-age academies also."
A number of senior private schools have already agreed to back academies, including high-profile Dulwich College in London and Wellington College in Berkshire.
Other private sector schools have switched to become academies themselves in response to falling pupil numbers.
Mr Hanson said it was likely prep schools would act as a co-sponsor, providing educational expertise.
His comments come before the conference of the IAPS, which starts in Liverpool on Monday.
Up to 400 headteachers will be encouraged at the conference to experiment with neuroscience in their schools. They will be addressed by American neuroscience expert Eric Jensen, who will talk about theories of effective learning.
Diana Watkins, the new chairwoman of IAPS and headteacher of Leaden Hall School in Salisbury, Wiltshire, said: "Our schools want to know about how to develop every aspect of a child's brain.
"Children need to be engaged, have things be relevant to them and be challenged."
Mrs Watkins said independent schools had more time to focus on developing the whole child because they were not as focused as state schools on league tables and key stage test results.
"The national curriculum allows for rigour and creativity. What do not are the assessments, which are numbingly boring," she said. "League tables mean that time is wasted teaching to the test when it could be used expanding the curriculum." She added that it was natural for teachers to focus on getting a narrow set of results when that was how they were judged.
Mrs Watkins, who abandoned key stage testing in her own school, estimated that around one in three prep schools continue to do the tests, mainly in areas where there are grammar schools or where larger numbers of pupils go on to state secondaries.