Nearly a third of schools say they will definitely not offer the new world-class tests designed to stretch the brightest sixth-formers, according to the analysis of nearly 1,250 schools.
The exams, known as advanced extension awards, are intended to be used by universities to discriminate between candidates with equally good A-level results.
Few pupils - less than 7 per cent - will take more than three A-levels, despite government attempts to broaden students' studies, according to the interim findings of the survey by the Universities and Colleges Admissions Service which looked at a total of 3,520 schools.
Hardly any students are expected to study five subjects in their first sixth-form year.
These findings will disappoint ministers who had originally wanted all sixth-formers to study five subjects in thir first year. Protests from headteachers forced them to lower their expectations to "up to" five.
Now the survey reveals that more than 80 per cent of sixth-formers are expected to study only four subjects in their first year, dropping one course when they go into the second.
Students will be able to take a new AS exam, worth half an A-level, before choosing whether to concentrate on three or more subjects in the second year.
Mixing and matching academic and vocational qualifications is likely to be popular with students, with two-thirds of schools planning to offer advanced general national vocational qualifications - renamed vocational A-levels - alongside traditional A-levels.
John Dunford, general secretary of the Secondary Heads Association, said that anecdotal evidence suggested that sixth-formers will not mix science and arts courses. "There has been a lot of talk about science students taking up a language and arts students studying maths. But it does not look as if that will happen."