A federal judge in Chicago is handing a significant victory to terrorism victims seeking to seize Iranian artifacts from the University of Chicago and the Field Museum.

In a ruling released yesterday, Judge Blanche Manning ordered the Iranian government to produce its records about how tens of thousands of ancient tablets and other antiquities ended up in the university’s collections.

In a five-page decision, Judge Manning rejected each of Iran’s arguments against allowing discovery in the case. The Islamic Republic’s claims that such procedures would lead to similar actions against America and other countries were “overblown,” she found.

The Rhode Island-based lawyer leading the effort to claim title to the artifacts, David Strachman, said the ruling will send an important message to Iran.

“They’ve been told now, if they want to play in the United States, they have to comply with federal law with respect to litigation and provide information that we’ve been doggedly seeking for just about two years,” Mr. Strachman told The New York Sun yesterday. “We’re pleased.”

Iran’s attorney in the case, Thomas Corcoran Jr. of the Washington-based Berliner, Corcoran & Rowe, did not return a message seeking comment for this article.

The dispute over the Iranian antiquities stems from a bombing on Jerusalem’s Ben Yehuda pedestrian mall in 1997 that killed five people and wounded almost 200. Hamas, which is financed and trained by the Iranian government, claimed responsibility.

Mr. Strachman sued on behalf of several victims and won a $251 million default judgment against Iran in 2003 from a federal judge in Washington, Ricardo Urbina. The lawyer moved soon thereafter to seize the artifacts, after reading that the university was planning send batches of them back to Iran.

Initially, Iran stayed on the sidelines while the Chicago-based institutions fought the seizure effort by claiming that the Islamic Republic’s properties in America are generally immune from legal action. However, when Judge Manning ruled in 2006 that only Iran could make such a claim, Tehran retained Mr. Corcoran and made a rare formal appearance in an American court.

The artifacts have a complex history. Some were sold to the University of Chicago in the 1940s by a prominent German archeologist, Ernst Herzfeld. In the 1930s, he led the university’s expeditions to Iran, but he was later fired by the school, after reports that some of the items might have been illegally obtained.

Mr. Strachman contends that the American government has sided with Iran’s stance in the case. In November, the Justice Department urged that Iran, as a sovereign nation, be treated with “grace and comity” in any discovery related to the antiquities. However, the American government did not take a firm stance for or against the effort to seek records from Iran. A Justice Department spokesman had no comment yesterday in response to an inquiry about the judge’s ruling. The Iranian U.N. mission in New York said it could not immediately respond to a request for comment.

Discovery rulings, such as the one issued by Judge Manning, are not normally appealable, though it is possible the Iranian government or even the Justice Department might seek special leave to pursue an appeal.

An Iranian-American attorney who led a petition drive opposing the seizure of the artifacts by the terror victims and their heirs, Jamshid Irani of Manhattan, said yesterday that the ruling may force Iran to negotiate.

“My feeling is this puts more pressure on the Iranian side to sit down and talk with the plaintiff, if not directly indirectly,” he said. “They are going to have to face reality.”

Mr. Irani took no issue with the judge’s ruling, but said the collections should not be auctioned or placed in private hands. “These are belonging to the Iranian nation, not necessarily the Iranian government,” he said.