The nine-member delegation, representing the Secondary Heads Association (SHA), the Girls' Schools Association (GSA) and the Headmasters' Conference (HMC), were making an unprecedented joint approach to the Government to put forward a common agenda for reforming 14-19 education.
They described the meeting last week with Education Secretary Gillian Shephard and other education ministers as "very positive".
They want a continuous and coherent system for 14 to 19 education, which would retain A-levels but encourage flexibility, credit accumulation and transfer, and a new over-arching qualification.
A recent joint statement from the three associations, plus the Association for Colleges, the Association of Principals of Sixth-Form Colleges, and the Society of Headmasters and Headmistresses in Independent Schools, called for a coherent education system for 16 to 19-year-olds. SHA, GSA and HMC, however, as secondary organisations are also concerned about 14 and 15-year-olds.
John Sutton, SHA's general secretary, who said the meeting was "excellent, " added: "We were there to persuade the Secretary of State that despite the five-year moratorium, it was necessary to move ahead on 14 to 19 in an evolutionary manner. I think we met a very positive response."
The heads argued that all students staying on at school until age 18 should aim for a common qualification. The route to ACE could be traditionally academic via A-levels, or a combination of the General National Vocational Qualifications and A-levels, they argued. And the AS level, which is supposed to be half an A-level, would be reformed to run over one year in Year 12. Students could then use it as a free-standing qualification or continue with it to a full A-level in Year 13.
The present system, involving GCSE, National Vocational Qualifications, A-levels AS-levels and GNVQ, had many attractive features, they said, but they needed to be drawn together, so that students could identify their own pathways through to 18.