Pupils need to take more vocational courses, according to Ofsted.

Under the Curriculum 2000 reforms, sixth-formers were expected to study up to five subjects at AS-level, before focusing on three subjects at A2, the second half of the new-look A-level.

But Ofsted chief inspector David Bell said: "The range of subjects taken has not broadened significantly, and the scope of teaching within subjects has narrowed, as teachers have concentrated on course specifications."

The "underlying weaknesses that Curriculum 2000 was designed to address", still had to be tackled, he added.

'Narrow focus'

However, the Department for Education and Skills said lessons had been learned and the situation was improving.

Ofsted's report follows the judgment by the inquiry into last year's A-level marking scandal, which said A and AS-levels should be split into stand-alone qualifications.

This would effectively mean a return to the pre-2000 set-up.

And in January, a "working group" was set up by Education Secretary Charles Clarke to produce proposals for a Baccalaureate-style replacement for A-levels, bringing the system in line with that of France.

Ofsted inspectors visited 110 state and private schools in England, as well as sixth form and further education colleges during the first two years of Curriculum 2000.

'Learned important lessons'

They found the large number of AS and A-level exams students had to take "led to a narrowing of focus" - the opposite of what the government had intended.

While most lower sixth formers took four subjects instead of the traditional three, it was "common" for them to drop one before they finished the first year.

Ofsted said "very few" schools and colleges required a mix of vocational and academic subjects, while they also had less time for extra-curricular activities such as sport and music.

Sixth formers were also not being told about the range of courses on offer, which included job-related modern apprenticeships.

Action should be taken to encourage students to "mix and match" much more, said Ofsted.

A Department for Education and Skills spokeswoman said: "This report only refers to the situation up until June last year and we have already learned important lessons from the early days of Curriculum 2000.

"Many of the issues raised by Ofsted have already been identified and action has been taken to tackle weaknesses and provide better support to teachers and students.