The deal marks the most significant progress in 15 years of on-and-off negotiations with the 11,000-strong Moro group on ending an uprising that has left more than 120,000 people dead, displaced about 2 million others and held back development in the south. Western governments have long worried that rebel strongholds could become breeding grounds for al-Qaida-affiliated extremists.
"The parties agree that the status quo is unacceptable," the 13-page agreement says. It calls for the creation of a new Muslim autonomous region called "Bangsamoro" to replace an existing one created in 1989 which Aquino characterized as a "failed experiment," where poverty and corruption have forced many "to articulate their grievances through the barrel of a gun."
The accord also calls for the establishment of a 15-member "Transition Commission" to work out the details of the preliminary agreement and draft a law creating the new Muslim autonomous region in about two years.
Rebel forces would be deactivated gradually "beyond use," the agreement says, without specifying a timetable.
The Philippine government would continue to exercise exclusive powers over defense and security, foreign and monetary policy in the new autonomous region, where Muslims would be assured of an "equitable share of taxation, revenues, and the fruits of national patrimony ... and equal protection of laws and access to impartial justice," according to Aquino.
Philippine officials said the preliminary accord would be posted on the government's website for public scrutiny, and would be signed in Manila in the presence of Aquino, Malaysian Prime Minister Najib Razak and Moro rebel chief Al Haj Murad Ibrahim.