Cease-fire monitors from Malaysia, Brunei and Libya were credited with drastically curbing clashes between government troops and the 11,000-strong Moro Islamic Liberation Front between 2004 to 2007, when they left after peace talks broke down.

The Moro rebels have waged a decades-old insurrection for self-rule in the Mindanao region in a conflict that has killed more than 120,000 people and held back economic growth in some of the country's poorest regions.

The United States and Australia have backed the talks, fearing rebel strongholds could harbor Al-Qaeda-linked militants.

"This is a very concrete sign that the peace process is back on track," chief government negotiator Rafael Seguis said during a ceremony for the foreign truce monitors late Sunday in southern Cotabato City.

Government officials and the rebels resumed talks in January following a yearlong hiatus. Both sides will meet Thursday in Malaysia, which has brokered negotiations after the guerrillas rejected a government autonomy offer, Seguis and the rebels said.

The Philippine Supreme Court in 2008 declared unconstitutional a preliminary peace pact, leading to fierce fighting that killed hundreds and displaced about 750,000 people. Clashes subsided last July, but about 100,000 people remain displaced, according to the International Committee of the Red Cross.

The monitors will be deployed in three southern cities to prevent any conflict from escalating into full-blown fighting that could derail the talks, Seguis said.