The figures are contained in a survey by the Department for Education of 16 year olds at the end of compulsory education in England and Wales.

The survey of 25,000 students' results last year showed that black and Indian students had made the biggest strides.

It found that 8% more gained five GCSEs at the best grades, A*-C, than two years ago, compared with an average improvement of 3%.

A spokesman for a Birmingham-based mentoring group which works with African-Caribbean boys said the new figures reflected what they had been seeing locally for some time.

Guy Woollery of the Kwesi project, which works with Birmingham schools to prevent exclusions, said exam pass rates for black boys had been improving slowly for the past two years.

'Give us more'

"There is still underachievement but the trend is now upwards," he said.

He called for more resources to be channelled to those working with black children, adding that the role of groups such as his in improving the behaviour and academic achievements of black students was not adequately recognised.

The survey follows a report last year commissioned by the Office for Standards in Education (Ofsted) which found that the achievement gap between 16-year-old white pupils and their Pakistani and African-Caribbean classmates had doubled since the late 1980s.

The new research showed that black pupils had moved ahead of their Pakistani counterparts, with 37% now achieving five A*-C grades at GCSE compared with 30% of students of Bangladeshi and Pakistani origin.

Bangladeshi concerns

The Education Secretary, David Blunkett, said there was work to do to reverse the decline in results achieved by Bangladeshi young people.

They dropped back from 33% getting five good GCSEs to 30%.

Mr Blunkett said the Bangladeshi community tended to be concentrated in particular areas such as Tower Hamlets in east London where the focus over the last couple of years had been on boosting achievement in primary schools.

"It may well be that that has resulted in some reduction in the attention given to older children.

"We need to examine what the causes are and very rapidly do something about it.

"For Indian and Chinese families there is terrific commitment from the home background - if we can assure that is repeated with Bangladeshi families I think we will see a big change."

Class differences

Analysis of results by parents' occupations showed that the biggest gains had been made in families where the earner was an unskilled manual worker, up from 20% to 30%.