The leader of the Philippines' largest Muslim rebel group is optimistic about the signing of a peace deal with the government, the group said on its website Sunday.

Moro Islamic Liberation Front (MILF) chairman Murad Ebrahim acknowledged as a "breakthrough" an agreement signed in April where both sides committed to create a new autonomous political region in the troubled south.

"This document serves as the guide in the discussion over the negotiating table on the details of a peace accord between the two parties," Murad was quoted by the rebel-controlled www.luwaran.com website as saying.

Murad's comments were the first since the agreement was reached in April, and showed a "commitment" from the MILF leadership to peacefully resolve the insurgency that has claimed over 150,000 lives since the early 1970s, the site said.

Murad said no dates had been firmed up for the next round of talks.

He added that both sides now had to decide on the "transitional mechanism and authority" of the proposed autonomous region for the talks to move forward.

The MILF has waged a rebellion for more than three decades, originally for the establishment of an independent state in Mindanao, the southern third of the mainly Catholic Philippines.

In recent years it has dropped its bid for full independence in favour of autonomous control over large areas in Mindanao, which it claims as Muslims' 'ancestral domain'.

The government has said it wants to broker a peace deal by next year so that it can be implemented by the time President Benigno Aquino leaves office in mid-2016.