A third of the 100,000 papers sat at independent schools were awarded a grade A, while 25% received a grade B.

The overal pass rate at grades A to E in these schools was 96%, slightly up on last year.

More than 33,000 students sat A levels at independent schools in the UK in 1998.

Their results compare favourably with the national statistics for A levels, which were published last week as candidates in England, Wales and Northern Ireland received their results.

The national picture, which includes the 800,000 papers taken at state and independent schools, saw 16.8% receive A grades and 18.9% get B grades. The overall pass rate at grades A to E was 87.8%.

'Wisdom'

The Independent Schools Information Service is highlighting the pass rate for grade As at fee-paying schools, which is twice the national average.

Its National Director, David Woodhead, welcomed the figures.

"Independent schools' reputation for academic excellence receives another boost with this year's A level results," he said.

"Their 33,000 candidates gained more A levels at higher grades than ever before, proving the wisdom of parents' investment in the independent sector."