The Sudanese Liberation Movement's leader Minni Minnawi accepted the deal but said that his group still had reservations about power sharing and sufficient representation in parliament.
Representatives of the remaining two factions, the Nur and the Justice and Equality Movement, walked out of negotiations before dawn on Friday. They rejected the agreement over security concerns and a disagreement over appointing a top presidential adviser from Darfur instead of a vice president as they wanted.
Although the rebels are united in accusing the government of neglecting the Darfur region, they have been deeply divided over how to approach the talks because of leadership rivalries. Those rivalries now threaten the agreement, since analysts questing how useful a peace deal could be if only one of the three factions agree to it.
A spokesman for the Nur faction said the group was meeting to discuss the agreement and reports indicated some within the group were leaning towards endorsing the pact. The African Union's special envoy to Sudan said he expects the Nur to return to negotiations later Friday.
Envoys from the African Union, the United States, Britain, the European Union and the Arab League joined the central government and rebel groups at the talks in Abuja, Nigeria. Negotiators twice extended the original deadline of April 20 as talks dragged on. The African Union began talks over power sharing, wealth distribution and security two years ago between the central government and rebel groups in Darfur who took up arms against the government in early 2003.
With the support of Western negotiators working to win the support of rebel factions, the current draft includes stronger security guarantees for Darfur, including provisions for rebel fighters to join the Sudanese armed forces and a requirement for Sudan to disarm its proxy janjaweed militias.
The central government agreed to the AU draft and has also accepted the revisions.
"The priority for us is peace and the priority for us is to alleviate the humanitarian situation in Darfur," said Majzoub al-Khalifa, head of the government's negotiating team.
In an interview with the NewsHour on Thursday, U.N. Secretary-general Kofi Annan said a peace deal was the number one priority in Darfur and expressed confidence that an agreement would help stop the violence.
"But it has to be a serious agreement, an agreement that will stand the test of time and make a difference on the ground, not something patched up that doesn't hold," he said.
Annan said the next step is to strengthen the AU forces to help them provide better security for displaced Darfurians and refugees while preparing to transition to a U.N. peacekeeping force.
On Thursday, President Bush said the United States recognized that the violence in Darfur must be stopped.
"That's why I believe strongly that we must augment [African Union] forces with a blue-helmeted UN force, with a NATO overlay, so that we send a clear message to the leader of Sudan: We will not tolerate the genocide taking place in that country," he said.
The Sudanese government opposed replacing African Union forces with U.N. peacekeepers but has indicated it will yield if a peace treaty was signed.