NEW YORK — The U.S. government is violating the First Amendment rights of key partners in its international fight against AIDS with a policy forcing groups to denounce prostitution as a condition for receiving funding, a federal judge ruled yesterday.

U.S. District Judge Victor Marrero said the U.S. Supreme Court "has repeatedly found that speech, or an agreement not to speak, cannot be compelled or coerced as a condition of participation in a government program."

The judge wrote that the government's "somewhat cavalier take-it-or-leave-it answer to an infringement of speech - which can more or less be characterized as 'if you don't like it, lump it' - is simply not in keeping with the expectations our society derives from First Amendment freedoms."

Marrero ruled after hearing arguments three weeks ago from the government and lawyers for three health organizations. Marrero asked both sides to propose a preliminary injunction within two weeks that conformed with his findings, which temporarily blocked the government from continuing the actions while the legal case continued.

Lawyer Rebekah Diller had argued on behalf of the health organizations that the government had created "a First Amendment nightmare" with the rules. She said she was "thrilled" with the judge's ruling.

"It's really a tremendous victory for public health," she said. "It will enable these organizations to serve very vulnerable women."

Assistant U.S. Attorney Richard E. Rosberger, arguing for the government, had said no provision of the 2003 law containing the anti-prostitution pledge requirement was meant to discourage the treatment of those with AIDS, including prostitutes.

A spokeswoman for the U.S. attorney's office in Manhattan, Megan Gaffney, said the government had no immediate comment on the decision.

Nongovernment organizations have long been significant partners of government in administering vital services, Marrero said, and should receive the quality of First Amendment rights and protection that editorial opinions or universities receive.

He wrote that the extent to which the government had prevented the organizations from speaking openly even with their private funds "contravenes our national commitment to open debate and our First Amendment values."

The judge wrote in his 115-page ruling that the government's asserted interest in eradicating prostitution may not be entirely inconsistent with the aims of the groups to reach out and empower prostitutes in the fight against HIV and AIDS.

He noted that evidence in the case showed that a program in Calcutta, India, in which groups work with prostitutes, reduced prostitution overall in the region where the program operated.

He said the program not only helped to produce low rates of HIV infection among prostitutes but also contributed to a decrease in prostitution as economic and social barriers to exiting the sex industry were eased with social programs for prostitutes.

Rosberger had argued to the judge that the United States formed a policy to eradicate prostitution and sex trafficking worldwide to reduce behavioral risks associated with HIV and AIDS.

The plaintiffs - the Alliance for Open Society International Inc., Open Society Institute and Pathfinder International - have adopted policies acknowledging prostitution's harms, but they object to being told how to execute them.

Pathfinder International, the largest of the three, is based in Watertown, Mass. It does work in more than 20 countries with 600 employees and an annual budget of $76 million.

The groups say the government policy would prevent anyone from advocating the legalization of prostitution or urging those working in the sex trafficking business to organize or unionize.

After Congress passed the bill, it was immediately applied to foreign-aid recipients, but the Department of Justice questioned the constitutionality of applying it to domestic organizations. In late 2004, the department cleared the government to implement the requirement domestically.

The lawsuit was brought in Manhattan in September. A similar lawsuit is pending in Washington, D.C.

The rules now affect private U.S. groups conducting AIDS programs overseas. To qualify for federal money, a group must adopt a statement and sign a form saying it opposes prostitution and sex trafficking. Only then is the organization eligible for funding.

Besides the pledge, the rules require AIDS groups to inform clients of condom-failure rates. They also require the government to give equal opportunity to funding applicants that have "a religious or moral objection" to a particular AIDS prevention method or treatment program, such as condoms or needle exchanges.

Diller, the plaintiffs' lawyer, said the government "can't be in the business of forcing public health organizations to make pledges on unrelated issues to do serious lifesaving HIV prevention."

She added: "The government was arguing for an extraordinary revision of well-established First Amendment principles. It's been clear that when the government spends funds, it doesn't have license to restrict the privately funded speech of funding recipients."