Indonesian officials and rebels battling for a separate homeland in Aceh province on the tip of Sumatra island signed a peace agreement today that could end one of the longest-running insurgencies in Asia.

The accord, signed in Geneva by top representatives of Indonesia and the Free Aceh Movement, calls for a cease-fire and partial demilitarization accompanied by discussions over how to provide greater autonomy to the 4.1 million people who live in the province. These talks would culminate in an election for a regional assembly in 2004.

The accord falls short of the rebels' long-standing ambition for independence in a region with generous oil and gas reserves. It also does not satisfy the demands of many Acenese that Indonesian military officers be held to account for what human rights groups say is a long record of atrocities against civilians.

The agreement culminates two years of negotiations involving international mediators, including retired Gen. Anthony C. Zinni, the former chief of U.S. Central Command, and includes significant concessions by Indonesia.

President Megawati Sukarnoputri has offered Aceh the right to retain up to 70 percent of the revenue from its oil and gas production and to implement Islamic law, or sharia, which is not generally enforced elsewhere in the country. These steps to address the aspirations of Indonesia's fiercest separatists reflect the priority Megawati has placed on preventing her vast and restless archipelago from splintering.

Aceh's guerrillas first took to the battlefield about 130 years ago, waging a furious uprising against Dutch colonialists that continued into the 20th century. The latest insurgency erupted in 1976, and an estimated 12,000 people have died in the conflict during the last decade.

"This is a good starting point," Zinni told the Associated Press. "But it is just the beginning, not the end."

Under the pact, the two sides would immediately end hostilities and begin rebuilding the province. Indonesia and the rebel movement would pull back their forces to positions designated by a joint security committee.

The first major test for the accord could come in two months, when the rebels are required to begin turning over their weapons to cantonment areas under international supervision. Indonesia, meanwhile, must withdraw most of its troops from the province, including paramilitary police brigades that have a reputation for brutality.