Under the deal, signed on April 15 but confirmed by the United States Central Command only today, United States forces agreed not to damage any of the group's vehicles, equipment or any of its property in its camps in Iraq, and not to commit any hostile act toward the Iranian opposition forces covered by the agreement.

In return, the group, the People's Mujahedeen, which will be allowed to keep its weapons for now, agreed not to fire on or commit other hostile acts against American forces, not to destroy private or government property, and to place its artillery and antiaircraft guns in nonthreatening positions.

The accord is apparently the first between the United States military — which in early April was bombing the group's Iraqi camps — and a terrorist organization, and it raises questions about how consistently the Bush administration intends to apply a policy that had vowed to crack down on terrorist groups worldwide.

It has carried out dozens of bombings that were aimed at Iranian military and government workers, but that also killed civilians.

It was added to the State Department's list of terrorist organizations in 1997. 

An American military official said the group could provide intelligence regarding Iranian government activities both in Iraq, and in Iran itself.

A spokesman for the Central Command, in Doha, Qatar, who was responding to a reporter's inquiry, issued a three-sentence statement today that provided the basic outlines of the cease-fire.

A senior military officer said he expected the accord to be followed in the next few days by a formal capitulation agreement, and he indicated that the group would eventually have to give up some of its arms.

The accord with the People's Mujahadeen reflects a pragmatic approach to a security problem for an American military that already has its hands full trying to stabilize Baghdad and other areas of Iraq. But it raises the issue of how to square the accord with the administration's antiterrorism policy.

A State Department official said tonight that the deal was not inconsistent with the broader effort against terrorism. The official said the agreement with the group, which operated with support and protection from Saddam Hussein's government, would help the United States learn more about Iraq's ties to terrorism and the nature of its former government.

"You can't get information out of a dead man," the official said. He said the decision to call a halt to American bombing and other attacks against the group did not reflect any change in its terrorist status. "It's a cease-fire," he said, "that's all it means."

As recently as last week, senior Pentagon officials described the group as a vicious entity that had served as a de facto security organization for the Iraqi government. At the same time, however, supporters of the People's Mujahadeen, including dozens of members of Congress, have portrayed the decision to label the group as terrorist as one that was taken by the Clinton administration largely as a positive gesture to the Iranian government, which regards the People's Mujahadeen as a serious foe.

A senior American officer said several approaches, or "courses of action" were being considered by the United States government as to what to do about the group and its weapons over the long run.

Asked why American commanders would sign a cease-fire with a terrorist organization, a Central Command spokesman, Lt. Cmdr. Charles Owens, said he had no further information. He noted that the State Department was responsible for decisions about the status of terrorist groups.

At a time when United States forces are stretched thin in Iraq, the Mujahadeen organization is one of the few groups of armed fighters that had been affiliated with the Hussein government that is not a threat to American forces, they said. American military officers in Iraq said they expected that some of the group's weapons might be confiscated once the capitulation agreement was signed.

One motivation for allowing the People's Mujahadeen to keep some weapons, they said, was to leave in place a balance of power between the group and the Iranian-backed fighters known as the Badr Brigade. Some of those fighters are based in Iraq and have continued to focus on the organization even since the fall of the Hussein government. If the Mujahadeen group were disarmed, American forces would have to assume the responsibility of separating the two antagonists, a task the heavily burdened American forces do not want to assume.

Muhammad Mohaddessin, a top People's Mujahadeen official, said in a telephone interview from Paris that "this cease-fire agreement gives us the right to keep our weapons in noncombat formations and the right to defend ourselves" against attacks from Iranian-backed forces. None of the group's members had been taken into custody by American forces, Mr. Mohaddessin said.

The statement issued by the Central Command said the cease-fire had been signed by "a coalition forces commander and a Mr. Mahdi Baraie of the National Liberation Army of Iran," the armed wing of the Mujahadeen organization.

Military officials declined to identify the "coalition forces commander," but senior military officers said the agreement was being enforced in areas north of Baghdad under the control of the Army's V Corps. Mr. Mohaddessin, the People's Mujahadeen official, identified Mr. Baraie as a senior official of the organization and a member of its army's general staff.

As recently as April 22, the Central Command spokesman in Doha, Brig. Gen. Vincent K. Brooks, declined to say whether a cease-fire with the People's Mujahadeen, known to the United States government as the Mujahedeen Khalq, or M.E.K., had been signed.

"We certainly know that the United States has maintained the M.E.K., as we describe it, on the terrorist list, and they still are," General Brooks said at the time. "So, until that changes, we view them that way. However, there's still discussion that's ongoing right now to determine exactly what the condition and what the status will be and how we'll handle them. It's premature for me to describe exactly what that will be at this point."

The disclosure that a cease-fire had been signed on April 15 suggests statements by American officers lagged events.

On April 17, General Brooks said at a briefing in Doha that work intended "to secure some agreement that would be a cease-fire and capitulation" would "most likely unfold within the coming days."

A senior military officer said a formal capitulation from the group was likely to be taken in coming days by the Army's Fourth Infantry Division, which is conducting peace enforcement in Tikrit and areas in northern Iraq.