Muenster, Germany - The controversial powers of German schools to compel Muslim girls to attend swimming lessons with boys in the pool were affirmed Tuesday by a tribunal.

The ruling came just five days after a federal convention had appealed to German schools to end compulsion on the issue, which has antagonized some of the Muslims who make up 5 per cent of Germany's population.

Judges in Muenster said a school in Dusseldorf was entitled to make entry conditional on a written undertaking from parents that their daughter, 11, would attend mixed swimming lessons.

The parents had contended to the administrative tribunal in Muenster that the undertaking was void, and asked that their daughter, now 12, be excused from mixed classes.

The school said the only acceptable solution was for the girl to wear a full-body swimsuit.

Some Muslims say semi-undress in mixed groups breaches Islamic precepts about modesty.

A survey has shown that only 7 per cent of Muslim girls actually do skip swimming classes. But the practice of barring Muslim children from elite schools if they refuse to conform has resonated through the Islamic community.

Last week a conference of German officials and Muslim leaders in Berlin appealed to public schools to segregate pool lessons if need be to defuse the long-running conflict with parents.

A legal document drafted by the conference said freedom of religion meant older girls had a constitutional right to refuse mixed swimming, but just not learning to swim was a "second-best solution."(dpa)