By DEXTER FILKINS and ROBERT F. WORTH - September 2, 2005

BAGHDAD, Iraq, Aug. 28 - Iraqi leaders presented a disputed constitution to the country's parliament on Sunday, overriding the objections of Sunni negotiators, sending the document to voters and setting the stage here for a protracted period of political conflict.

The Sunni negotiators, who included former members of the Baath Party of Saddam Hussein, publicly denounced the constitution and called on Iraqis to send it down to defeat when it goes for a vote on Oct. 15. Some Sunnis said they expected guerrilla violence to surge.

A Sunni member of the constitutional committee, Mahmoud al-Mashadani, said, "We have reached a point where this constitution contains the seeds of the division of Iraq."

In the face of those developments, President Bush, at his ranch in Crawford, Tex., praised the constitution as a milestone in Iraqi history, congratulating Iraqi leaders for "completing the next step in their transition from dictatorship to democracy." Mr. Bush emphasized what he described as the charter's protections for individual rights, and he tried to allay concerns about opposition from Sunni leaders.

"Some Sunnis have expressed reservations about various provisions of the constitution, and that's their right as free individuals living in a free society," he said. "There are strong beliefs among other Sunnis that this constitution is good for all Iraqis and that it adequately reflects compromises suitable to all groups."

The Iraqi leaders, a group of mainly Shiite and Kurdish representatives, said they had decided to push ahead with the constitution after Sunni leaders submitted a new list of demands.

The American ambassador here, Zalmay Khalilzad, who had vigorously worked to bring the Sunnis into the deal, said he, too, had given up in frustration.

The leaders entered the National Assembly chambers in the early afternoon, read the 39-page document aloud and urged them to go out and persuade the people in their communities to vote for it in October.

Then the group, made up of about 40 of the most powerful political leaders, drove across the Green Zone to the palace of the president, Jalal Talabani. In a ceremony held in the courtyard, they declared the constitution the embodiment of the nation.

Yet only four Sunni Arab leaders attended the event, and all had been longtime exiles. There were some noticeable absences: Adnan Pachachi, the former foreign minister; Ghazi al-Yawar, the former president; and Ayad Allawi, the former prime minister and secular Shiite leader.

President Talabani, though casting a mostly positive light on the day's events, expressed frustration with the Sunni negotiating team, a group hastily brought into the drafting process by Iraqi and American officials after the Sunni boycott of the elections in January.

The 15 Sunni representatives took such a tough approach to the negotiations that several Shiite and Kurdish leaders said privately that there was no deal they would agree to.

"We didn't have elections that determined that these people would actually represent the Sunni Arabs," said Mr. Talabani, a Kurd. "They say they talk in the name of those who did not participate in the elections."

The fractured outcome appeared to leave the Bush administration's political strategy here in disarray and to complicate its plans to reduce the number of American troops. Since January, one of the principal aims of America's policy here has been to bring the Sunnis, who largely boycotted the polls in January, into the political process, first by drafting them to help write the constitution, and then hoping to persuade them to go to the polls in parliamentary elections set for December.

The hope of the Bush administration has been that the Sunnis, who dominate the insurgency, would turn away from violence once they saw the benefits of political participation. In recent weeks, Sunni leaders in towns north and west of Baghdad had begun calling on people to register to vote and to take part in the political process, with a cleric in Falluja even issuing a fatwa, or holy injunction, requiring voting.

All of that now seemed to be in danger. Indeed, the likelihood of a divisive referendum raised the prospect that the constitutional drafting process was not uniting the country but helping drive it further apart.

Under the constitution, the Kurdish region would be given a degree of autonomy that would divorce it in most respects from the central government; in time, southern Iraq could follow in a similar way.

In a news conference, Mr. Khalilzad, the American ambassador, told reporters he was "disappointed" by the Sunni representatives' decision to oppose the constitution.

"I was hoping their reaction would be more positive," he said.

Mr. Khalilzad acknowledged that it was possible the document would be voted down in October, because electoral law allows a defeat if a two-thirds majority in 3 of Iraq's 18 provinces vote against it.

Recognizing the difficult road head, he repeatedly urged Sunnis to "read the document, and don't listen to what others are saying about it."

Mr. Khalilzad and some Iraqis left open the possibility that they might consider further changes to the document. But with only six weeks to go until the referendum, and plans in the works to distribute five million copies of the constitution to the Iraqi people, the likelihood seemed slim.

The possibility that the three Sunni-majority provinces could bring down the constitution seemed, at least for now, to be fairly remote. Sunnis are a solid majority in two provinces, Anbar and Salahuddin, but only a slim one in Nineveh, which has a large Kurdish population.

But there seemed the possibility, at least for now, that voters in Baghdad could cast the decisive ballots against the constitution. Moktada al-Sadr, a rebel Shiite cleric and anti-American firebrand, has called out his followers to campaign against the constitution, in defiance of the Shiite leaders who wrote the charter. Sadr City, the sprawling district that is the base of Mr. Sadr's support, makes up nearly half the population of Baghdad, which is a province unto itself.

If the constitution is defeated, the law calls for new elections, after which yet another constitution must be written.

The handful of Sunni leaders who decided to support the constitution said they anticipated a difficult job trying to persuade the Sunni community, deeply embittered since the fall of Mr. Hussein, to vote for it.

"It is not going to be an easy task," said Hachem al-Hassani, a Sunni and the speaker of the National Assembly, of persuading other Sunnis to support the constitution. "They didn't get much of what they wanted."

Ambassador Khalilzad suggested that some of the 15 Sunni negotiators supported the constitution, but were afraid to say so publicly.

"There are threats of intimidation," he said. "Some are afraid that if they support it their lives could be at risk."

For at least a handful of the Sunni negotiators, like Mr. Mashadani, the threat of death appeared to play a role. Iraqi insurgent and terrorist groups, including Al Qaeda, have promised to kill any Iraqi who takes part in the constitutional drafting process. Two Sunnis on the committee were killed last month.

"The Iraqi street is dying, and if we approve this document we might be accused of measures that we are not guilty of," he said.

Sunni members of the constitutional panel said they had held a final meeting at noon, where they agreed to reject the draft constitution they had been handed the day before. They cited longstanding sources of disagreement, such as language that would allow the majority Shiite community to allow Iraq to be divided into autonomous regions.

The issue of Shiite autonomy highlighted the Sunni-Shiite divide. The Sunnis said they feared that allowing the Shiites to set up a huge autonomous area in the oil-rich south could be the first step in the dissolution of the country. Yet for many Shiites and Kurds, the Sunni reluctance to make a deal was really about their unwillingness to relinquish their dream of ruling Iraq, something they did almost without interruption from the country's birth in 1920 until the American invasion in 2003.

"The Sunnis must understand that they no longer have a monopoly on power," said Masoud Barzani, the Kurdish leader.

For such a momentous occasion, the 40-odd leaders who gathered in the courtyard of Mr. Talabani's palace evinced noticeable restraint. The gathering showcased the political elite of the new state: with the exception of the Kurds, who spent years in their American-protected enclave in northern Iraq, nearly all of the senior leaders had spent many years living outside Iraq. Some, like Ahmad Chalabi, wore Western suits, while others, like Sheik Humam Hamoudi, donned turbans and flowing robes.

The leaders praised the constitution they had produced, saying it reflected the consensus of their diverse country. The constitution would transform what was a secular state with a strong central government into what would probably evolve into a loose federation with a heavily Islamic character.

"It is a constitution for Arabs, Sunni and Shiites, for Kurds, for Caledonians, Assyrians, Christians and Muslims," said Mr. Talabani, once a guerrilla leader. "We hope our intelligent people will approve this constitution, stressing at the same time that we don't deny the deficiencies in it, and perfection is only for God."

Under the new constitution, Islam would become the official religion of the Iraqi state, and be regarded as "a main source of legislation." Clerics would more than likely sit on the Supreme Court, and judges would have broad latitude to strike down legislation that conflicted with the religion. Clerics would be given a broad, new role in adjudicating family disputes like marriage, divorce and inheritance. Under most interpretations of Islamic law, women enjoy substantially fewer rights than men.

The heavily Islamic cast of the constitution, influenced by the Shiite religious parties who won the January elections, has troubled many of Iraq's women and secular leaders, even with the constitution's many guarantees for religious freedom and individual rights. Mr. Hassani, the Assembly speaker and one of the few Sunnis to come out in favor of the constitution, said Sunday that he was quite unhappy with parts of it.

"This constitution has too much religion in it," Mr. Hassani said. "The rights of women; they took away a lot of the rights of women."

Even some Shiites and Kurds, for all their relief that the constitution was finally complete, expressed uneasiness about the way it was achieved.

"What is important for me is something that would make Iraqis feel more united," said Mahmood Othman, a Kurdish member of the constitutional panel. "That didn't happen."