A white supremacist group said yesterday it will sue the Baltimore County library system for blocking a World Church of the Creator recruitment meeting at the Rosedale branch next month, a move the self-described racists call a violation of their constitutional rights.

"It's purely political, purely political," said the Rev. John King, the Virginia leader of the World Church of the Creator, an anti-Semitic, anti-black group that works for "the survival, expansion and advancement of the white race."

But library Director James H. Fish said there is nothing unconstitutional about the library's decision.

He said administrators decided to refuse the church's request for a meeting room at the Rosedale branch Dec. 14 because the event would pose a threat to the safety of library staff, patrons and property.

According to the library system's "Meeting Room Policy Regulations," which anyone trying to reserve a room must sign, the library has the right to revoke permission to use a meeting room "upon adequate notice and for adequate reasons."

"This particular group has visited other libraries throughout the country," Fish said of the World Church of the Creator. "There are usually situations of the police having to be involved, of violence."

Protesters and World Church supporters clashed after a speech at a library in York, Pa., in the spring. Other meetings have proved uneventful, according to news reports.

King said it is not legal to prevent a group from meeting because of what protestors might do.

"We have never lost a battle such as this," the Rev. Matt Hale, the leader of the World Church of the Creator, wrote to Fish in a letter that was faxed to news media groups yesterday. "Yes, libraries have tried to block us, but they have lost in court. Contact your attorneys and have them research our victories."

Professor David S. Bogen of the University of Maryland School of Law said that the issue might come down to whether the library has a legitimate fear of violence, or whether it is using that fear as an excuse to exclude a group for its views.

"A library can't exclude on the basis of viewpoint," he said. "It may be able to exclude on the basis of the problems it may cause to the library operation."

The Baltimore County library system allows groups to reserve its meeting rooms for a fee - $30 for nonprofit organizations, $100 for for-profit groups.

If an organization is interested, it calls the library to tentatively reserve a date, after which the library sends it the meeting room policy sheet. After a group or person signs that form and returns it with a check, the library gives final confirmation.

Fish said that the library system, after talking with attorneys, decided against giving the group final confirmation and allowing it to meet. He called King yesterday morning to let him know, both men said.

Fish said the decision had nothing to do with the library's assessment of the views of the World Church of the Creator. The church, based in East Peoria, Ill., is described by the Anti-Defamation League as one of the fastest-growing hate groups in the United States during the 1990s.