Religious organizations can be sued for violations of federal antitrust laws, even though they claim that their business conduct was motivated by religious concerns and thus protected by the Constitution, the U.S. Court of Appeals ruled yesterday.

In a unanimous decision, the appeals court rejected arguments from Roman Catholic groups that claimed the First Amendment's guarantee of free exercise of religion absolutely protected them from lawsuits charging they had engaged in anticompetitive business practices in violation of federal antitrust laws.

Judge Patricia M. Wald, writing for the court, said that "while the freedom to believe is absolute," the courts have also recognized that some limits can be imposed "on the freedom to act in pursuit of religious beliefs."

The court said those limits, if any, must be determined by weighing the need to protect the free exercise of religion against the community's general interest in promoting free competition in the marketplace.

The case involved distribution by the New York-based Costello Publishing Co. of a book called Morning and Evening Prayer, which contains prescribed prayers translated from Latin to English and recited daily by the Roman Catholic clergy and laity.

The National Conference of Catholic Bishops charged that the book, which was based on a translation approved by the Irish Catholic hierarchy, was not authorized for distribution here.

When Costello refused to allow the bishops conference to review the book, the conference sent a memorandum to religious book dealers around the country, asking them not to distribute the Costello book. The conference was part of a worldwide group of English-speaking bishops that had approved their own version of the prayers for distribution in the United States.

Costello filed a lawsuit in U.S. District Court here charging that the church groups had violated federal antitrust laws by discouraging Catholic book dealers from distributing Morning and Evening Prayer.

In the District Court, Judge June L. Green ruled that the church groups' action was not motivated by commercial interest but was instead intended "to protect the integrity of the Roman Catholic liturgy worldwide." Green said that conduct motivated by religious concerns is not subject to the antitrust laws.

The appeals court, in reversing Green's decision, said that no such blanket exemption exists. The appeals court said that Green must first determine whether economic pressure was brought on the retailers by the church and, if so, whether it was geared to the church's protection of its liturgy "rather than its survival in the marketplace of religious books."