The Moro Islamic Liberation Front (MILF) has waged rebellion against the Philippines government since 1978
The Philippines said it had brokered a "significant" agreement Tuesday with Muslim rebels on how to end a decades-long insurgency, but warned that major issues still needed to be resolved.
Chief government negotiator Marvic Leonen said the breakthrough with the Moro Islamic Liberation Front (MILF) was achieved during the latest round of talks in Malaysia that began a decade ago.
"This marks a significant and concrete step forward by both parties in their discussions of the substantive issues in these negotiations," Leonen said.
He said both sides had committed in the initial broad agreement to create a new autonomous political region that would replace an existing one that has widely been regarded as a failure.
The two sides also agreed to work towards "power and resources sharing" in the proposed autonomous region, which would cover parts of the southern Philippines that the country's Muslim minority call their ancestral homeland.
However no details were provided on the exact areas that could be covered by the proposed new autonomous area.
Leonen acknowledged that Tuesday's agreement was not detailed or precise, and that they only laid the foundations for further "substantive negotiations".
"We look forward to the coming weeks of more thorough -- perhaps more difficult -- conversations with the MILF and various affected sectors," Leonen said.
MILF leaders were not immediately available to comment.
The two sides issued only a brief joint statement at the end of the talks announcing they had signed a document outlining "decision points on principles".
The government has said it wants to broker a peace deal by next year so that it could be implemented by the time President Benigno Aquino leaves office in mid-2016.
Demands by the 12,000-strong MILF, waging a rebellion since 1978, for the expansion of the existing autonomous region had met with Christian opposition and torpedoed previous attempts at a peace accord.
More than 150,000 people have died in the conflict, according to the Philippine military.