MANILA, Philippines — Muslim rebels and the Philippine government overcame decades of bitter hostility and took their first tentative step toward ending one of Asia’s longest-running insurgencies with the signing of a preliminary peace pact that provides both hope and challenges.

The framework agreement creates a roadmap for a final peace settlement. It grants minority Muslims in the southern Philippines broad autonomy in exchange for ending more than 40 years of violence that has killed tens of thousands of people and crippled development.

It was signed Monday in Manila’s Malacanang presidential palace by government negotiator Marvic Leonen and his counterpart from the Moro Islamic Liberation Front, Mohagher Iqbal. Also witnessing the historic moment were President Benigno Aquino III, rebel chairman Al Haj Murad Ebrahim — who set foot in the palace for the first time — and Malaysian Prime Minister Najib Razak, whose country helped broker the deal.

About 200 guerrillas and followers, all in dark business suits, joined the crowd of diplomats, officials, and police and army generals in a chandelier-lit hall to witness the signing. In their southern Philippine strongholds, thousands of guerrillas waved flags and gathered to celebrate.

“The framework agreement before us will bring to an end the violence which claimed so many lives, and cut short so many futures,” Najib said. He said the deal would protect the rights of minority Muslims while preserving the Philippines’ territorial integrity.

“After four decades, peace is within reach,” he said, adding that he hopes large numbers of Filipinos displaced by decades of strife, including many who fled to Malaysia, will be able to return to normal life.

But he cautioned that the agreement “does not solve all the problems, rather it sets the parameters in which peace can be found.”

The 13-page document outlines general agreements on major issues, including the extent of power, revenues and territory granted for a new Muslim autonomous region to be called Bangsamoro in the predominantly Roman Catholic nation. The large number of army troops will gradually be replaced by a regional police, which could enlist qualified guerrillas, officials and the rebels said.

It calls for the establishment of a 15-member Transition Commission to draft a law creating the new Muslim-administered region. The 11,000-strong rebel army will be deactivated gradually “beyond use,” the agreement says, without specifying a timetable.

The United States, which has deployed hundreds of counterterrorism troops in the southern Philippines since 2002, welcomed the signing, saying it “marks another step toward ending insurrection and restoring good governance.”

“The United States will continue to work with the international community, regional stakeholders and the people of the Philippines to promote transparency, governance, economic growth and development to achieve a better future,” said a White House statement.

Aquino also said much work remains to be done and “the devil is in the details,” but that his government is committed to the country’s south. Negotiations on a final peace pact will start next month in Malaysia and the two sides aim to finish drafting it this year, government negotiator Marvic Leonen said.

Murad said the agreement following “almost 16 years of hard negotiations interspersed with armed confrontations” is “a landmark document that restores to our people their Bangsamoro identity and their homeland, their right to govern themselves and the power to forge their destiny and future with their very hands.”

Sonny Davao, deputy chief of the rebel army, said guerrilla commanders were ready to shift from armed struggle to helping build a new Muslim-administered region.

“We have to transform ourselves because we have responsibilities and obligations to our people and to Islam,” said Davao, who shed his camouflage uniform for a dark coat and tie for the signing ceremony.

The agreement says the new Muslim-administered region will replace an existing autonomous territory consisting of five of the country’s poorest and most violent provinces.

That territory was created by a 1996 peace agreement with the Moro National Liberation Front, but was considered a failure because it did not end the conflict, the rebels did not disarm and it did not improve the lives of Muslims. Corruption, political violence and crimes such as kidnappings and extortion persisted, and the current Moro group continued to fight for self-rule.

Another preliminary accord in 2008 was struck down as unconstitutional because the Supreme Court ruled it would create a separate state.

Western governments have long worried over the presence of small numbers of al-Qaida-linked militants from the Middle East and Southeast Asia seeking combat training and collaboration with the Filipino insurgents.

One of those extremist groups, the Abu Sayyaf, is not part of any negotiations, but the hope is that the peace agreement will isolate its militants and deny them sanctuary and logistical support they had previously received from rebel commanders.

One of those hardline commanders, Ameril Umbra Kato, broke off from the main Moro insurgents last year. Kato’s forces attacked the army in August, prompting an offensive that killed more than 50 fighters in the 200-strong rebel faction.

Abu Misri Mammah, a spokesman for Kato’s forces, said Sunday that his group does not recognize the peace accord.

“That’s a surrender,” he said. “We won’t waver from our armed struggle and continue to aspire for a separate Muslim homeland that won’t be a creation of politicians.”

Michael Mastura, a member of the rebel negotiating team, said guerrilla leaders have to forge a strong peace deal that can withstand any opposition from hardliners.

“It is easy, just gather a few men and disturb, because there are many firearms around. But that’s not the mainstream line,” Mastura said in an interview. “That is why we have to show that this is the way rather than their way.”

Iqbal has said his group will not lay down its weapons until a final peace accord is concluded. He said the insurgents could form a political party and run in democratic elections to get a chance at leading the autonomous region.