The broad agreement, reached in Abuja, Nigeria after three weeks of often tense negotiations, committed the parties to upholding democracy by ensuring "justice and equality for all, regardless of ethnicity, religion and gender," the Associated Press reported.
"By adopting the declaration of principles, you have demonstrated your own determination that you will not let down the people of Darfur ... and you will not let down our friends in the international community," Salim Ahmed Salim, the African Union's chief mediator, told signatories.
Salim later told Reuters that the two rebel groups, the Sudan Liberation Army and the Justice and Equality Movement had helped lay the foundation for peace by signing the agreement but would have to take further steps to reach a full peace settlement.
The talks, which began June 10, have been stalled because of infighting among rebel leaders, with negotiators from within the movements often contradicting each other.
"Hopefully the (rebel) movements will be in a better position in terms of closing their own ranks," Salim said. "The discussion towards the comprehensive agreement is much more complex than the discussion on the declaration of principles."
Though Tuesday's three-page agreement proposed devolving powers from the Khartoum government to regional leaders, it failed to outline how best to disperse power or wealth, the AP reported, a key point of contention between rebels and the government.
In early 2003, the mostly black African rebel forces in Darfur took up arms against the Arab-dominated government, accusing the country's leaders of discrimination and oppression. One of the rebels' main arguments was the failure of the government to share assets from the country's oil rich regions.
In response, the government is accused of unleashing the Janjaweed, Arab militias who rampaged, burning and pillaging black villages and forcing over 2 million people from their homes. More than 180,000 people have died in the conflict, some at the hands of the militia, others from hunger and disease.
Talks to iron out power and wealth-sharing details will be held Aug. 24, mediators said.
The U.S. government has labeled the Darfur attacks genocide and the United Nations has called the conflict the world's worst humanitarian crisis.