By Gary Eason BBC News Online education editor

The A-level pass rate has shot up by 4.5 percentage points, from 89.8% last year to 94.3%.

The unprecedented one-year rise follows the first major overhaul of A-levels since their introduction 51 years ago.

Key features

701,380 A-level entries 47,486 fewer than last year pass rate 94.3% up from 89.8% girls 95.4% boys 93.0% 995,404 AS-level entries 201,287 more than 2001 pass rate 86.5%

Exam chiefs insist standards are being maintained and talk about "driving failure out of the system" - predicting a 100% pass rate within a few years.

The Welsh exam board, WJEC, is ahead of the game: 98.2% of its entries passed.

But overall there was a drop this year of more than 6% in the number of A-level entries, from 748,866 to 701,380.

The rising pass rate and the fall in entries are attributed to the "AS effect" - with weaker candidates being weeded out under the new system and not carrying on to do a full A-level.

The net effect is that about the same number of A-levels have been awarded.

Growing gender gap

The number of AS-level entries has gone up by a quarter, from 794,117 last year - the first year they were taken - to 995,404.

Standards are being maintained and achievements are rising John Milner, qualifications council

The AS-level pass rate was almost unchanged: 86.5% compared with 86.6% in 2001.

The A-level "gender gap" has accelerated, with 95.4% of girls passing and 93% of boys - a difference of 2.4 points, up from 1.9 last year.

The Vocational A-levels attracted 32,246 entries - being new, there are no equivalent figures for last year.

The pass rate was 78.7%. For boys it was 74% and for girls, 83% - a nine point difference.

The figures are for England, Wales and Northern Ireland and are provisional - they could change slightly as a result of late entries and appeals.

Students get their individual results on Thursday. The school-by-school "league tables" are issued towards the end of the year.

Standards

The overview of the results was issued on behalf of the exam boards by the Joint Council for General Qualifications.

Its convenor, John Milner, said this was "a fascinating year" with "the most exciting and important change since the A-level was introduced in 1951".

"Standards are being maintained and achievements are rising," he stressed.

Officials at the exams watchdog, the Qualifications and Curriculum Authority (QCA), have said they can foresee the pass rate reaching 100% within two or three years.

Mr Milner said: "The real question is how can we drive out failure in the system?" - so that all students made the most of their strengths.

Options

He said people had seized the opportunities afforded by the Curriculum 2000 changes and were making choices about the qualifications they wanted to pursue.

Anyone who thinks passing an A-level is easy is simply out of touch Sir William Stubbs, exams watchdog

No more was there "the dreadful problem" of perhaps 20% of candidates failing at the end of a two-year course.

The model that had been put forward when the changes were introduced was that students might typically do four or five AS-levels then focus on three A-levels.

In practice there was a range of options open to them - and they and their teachers were making informed choices, Mr Milner said.

But he said it what was not clear at this stage what had happened to the youngsters who had chosen not to go on and do an A2, as the second part of the A-level is now called.

It might be they were doing another AS or a three-unit Vocational AS-level or something else entirely.

Points mean places

Mr Milner said the exam boards, qualifications watchdog and, he presumed, the Department for Education, would want to commission research to try to discover the answer.

One reason students might choose to do another AS-level relates to the new tariff system of points for university entrance, which has been adopted by about 70% of the UK's universities.

The standard required to get an AS is less than half an A-level - whereas the second part of the course, the A2, is pitched at a standard higher than the old A-level.

Yet an AS commands half the tariff points of a full A-level.

'No surprise'

The general secretary of the National Association of Head Teachers, David Hart, said that far from broadening the curriculum, the changes had resulted in its narrowing as students played to their strengths to maximize their chances of getting a university place.

"At the end of the first year, students can drop their worst subjects or retake. Or they can concentrate on their strong subjects.

"Two AS-levels equals an A-level for university. That's why there's been a drop in A-level entries.

"Nobody should be the least bit surprised that students are getting better results."

But the president of Universities UK, Professor Roderick Floud, said the rise in AS entries was "a positive sign of growing breadth in the 16-18 curriculum".

He said it would lead to greater opportunities for young people to go on to choose the right course in higher education.

Review

The head of the QCA, Sir William Stubbs, said: "All those who have passed have achieved an award of lasting value.

"They can demonstrate to employers and educationalists they have real skills and abilities.

"Anyone who thinks passing an A-level - general or vocational - is easy is simply out of touch."

He added: "We will be reviewing this year's examinations outcomes overall and reporting to ministers in the autumn.

"We will consider whether fine-tuning is needed and look at further ways to ease the burden on schools and teachers while maintaining standards."