Black children are up to 15 times more likely to be excluded from school in some areas than their white classmates, according to a TES analysis of government figures.
Nationally, black pupils were at a 3.4 times greater risk of expulsion than white children in 199697, the most recent year for which centrally-collated figures are available for primary, secondary and special schools. But in some areas - including Trafford in Greater Manchester, Surrey, Essex and Sutton, London - that risk ran into double figures.
The Commission for Racial Equality said the figures were "extraordinary, " It would consider using its legal powers to investigate authorities with such differences.
A spokeswoman for the Department for Education and Employment this week revealed that it has written to 50 authorities with disproportionately high ethnic minority exclusion rates emphasising the need to set targets for reductions as part of their behaviour support plans.
The CRE has been campaigning for authorities to set such targets.
The figures cover local authorities which excluded four or more pupils in at least one ethnic minority grouping in 199697. Overall, pupils categorised as Black Caribbean or Black Other were more likely to be excluded than Black African children, and four times more likely to be excluded than whites.
Asian pupils are less likely to be excluded than white children except in some areas such as Bolton and Bury where rates for Pakistani children were about double the national average.
The worst regions were Merseyside and the South-west where rates were seven to nearly 10 times higher for black pupils.
Even in London, where most boroughs have large ethnic minority populations, the exclusion rates for varied significantly. For example, Black Caribbean pupils were seven times more likely to be excluded than whites in Islington - but only 3.7 times more likely in Southwark.
In Trafford and Surrey, black pupils were 15 times more likely to be excluded than white pupils. In Essex and the London borough of Sutton, the risk was 11.5 and 12.7 times greater respectively.
Essex and Surrey have very small ethnic minority populations, but Trafford and Sutton are closer to the England averages for secondary school pupils. Trafford had the second-lowest exclusion rate for white pupils - only 0.09 per cent.
Several other authorities have low total exclusion rates which disguise big variations between racial groupings.
Muriel McIntosh, Sutton's assistant director of education, said the numbers of ethnic minority children excluded were very small, giving a statistically-distorted picture. Sutton excluded four Black Caribbean pupils out 225 in 199697, compared to 30 out of 21,689 white pupils.
However, Sutton takes exclusions extremely seriously, she said. Exclusion and attendance are monitored by ethnic background.
Mike Barnett, a spokesman for Essex county council, said figures for 199798 showed non-white pupils were still at a higher risk, but less than in 19967.
Kathryn August, Trafford's director of education, also noted the small numbers involved.
Schools, not authorities, exclude pupils; but councils have been given responsibilities and government targets to reduce the number of exclusions by a third by 2002.