By Tom Heneghan, Religion Editor

PARIS (Reuters) - Germany's top administrative court agreed with Roman Catholic bishops on Wednesday that German believers who refuse to pay a special church tax could be shut out of Catholic worship.

The verdict, based on German corporate law, upheld the system by which the state collects religious taxes from registered Catholics, Protestants and Jews with their monthly returns and distributes them to the religious communities.

Reformist Catholics have decried the tax, introduced in the 19th century to compensate for confiscated church properties, as a "pay to pray" system. Conservative critics have asked why tax opt-outs are shut out but dissenting theologians are not.

"Whoever wants to officially leave a religious community that is registered as a statutory corporation cannot limit this withdrawal to the statutory corporation and remain a member of the faith community," said the Federal Administrative Court in Leipzig, the top appeals court in such issues.

The Church hailed the verdict as confirmation of its tax rule, which the bishops reconfirmed last week with a decree saying members who opted out of the tax could not receive sacraments, work in the Church or have a religious burial.

"The Church is a community of faith that exists in Germany in the form of a statutory corporation - they cannot be separated," Archbishop Robert Zollitsch, head of the bishops' conference, said after the verdict was announced.

The legal challenge to the tax began in 2007 when a retired professor of canon law told his local tax authority that he wanted to quit the institutional Catholic Church and stop paying its tax, but continue to practice the religion.

If the Leipzig court had ruled against the Church, it could have prompted a wave of departures from the religions that charge the tax, which amounts to 8 or 9 percent of earnings.

FULL COFFERS

Church taxes brought in about 5 billion euros ($6.5 billion) for the Roman Catholic Church and 4.3 billion euros for the Protestant churches in 2010, according to official statistics.

Those funds have helped both churches to run large networks of schools, hospitals and charitable works in Germany and contribute to churches abroad, but an exodus of members has lowered total revenues in recent years.

The annual total of Catholic church leavers, usually around 120,000, jumped to 181,193 two years ago as news of decades of sexual abuse of children by priests shamed the hierarchy and prompted an apology from the German-born Pope Benedict.

Zollitsch defended the tax decree during a meeting of the Catholic Church hierarchy in Fulda this week.

"Our concern is to show that whoever wants to belong to the Church must contribute to what the Church needs to do its work," he said on Tuesday. "There must be consequences."

German media have dubbed the new tax decree "excommunication lite" because it bars those who refuse to pay from almost all church activities - including becoming godparents or joining a church-run club - without saying they have been excommunicated.

The Catholic reform movement We Are Church said the tax decree was questionable under Church law because it had not been approved by the proper Vatican department.

"The bishops still have to explain theologically and legally what status these sanctions have," it said in a statement.

(Editing by Kevin Liffey)