Universities have been accused of taking a simplistic view of the new AS exam as evidence grows that they are rejecting it in favour of traditional A levels.
A study by London University's Institute of Education indicates that many universities are barely interested in the AS (advanced subsidiary) qualifications introduced last year as part of the Curriculum 2000 reforms in schools.
Ann Hodgson, joint director of the institute's lifelong learning group, said that there appeared to be a perception among admissions tutors that doing AS levels in year 12 detracted from final A-level performance in year 13.
Dr Hodgson said: "I do not believe that the less pupils do, the better they do. However, I think universities are taking this simplistic view. In fact, pupils are working harder."
Many schools have encouraged their year-12 pupils to take four subjects at AS level to give them greater academic breadth. They then take two or three of these AS levels to full A level the following year.
But the study shows that up to 15 per cent of year-12 pupils have dropped their fourth AS level in order to concentrate on the A levels they will sit the following year. Dr Hodgson blamed pressure from universities and parents for the decline.
She added that problems with the new curriculum would be compounded next year if applicants found that university admissions tutors were interested only in A-level results. That information would percolate down to schools and fewer pupils would choose to opt for a fourth AS level.
The institute's research also found that universities were even less interested in the new key skills programmes introduced as part of Curriculum 2000.