The Sudanese government and two rebel groups have agreed on ground rules for efforts to resolve the conflict in the troubled Western region of Darfur.
Rebels began an insurrection in Darfur in 2003
They signed a declaration of principles after four weeks of hard negotiations in the Nigerian capital, Abuja.
The principles include democracy and devolution. But African mediators warn that formidable challenges remain.
About 180,000 people have been killed and more than two million made homeless since the conflict began in early 2003.
The Khartoum government and Arab militias have been accused of widespread atrocities against black Africans in Darfur.
A recent United Nations report stopped short of saying the authorities and their militia allies carried out a genocide, but it did say war crimes had been committed.
Talks mediated by the African Union (AU) began in August of last year with the aim of finding a political solution.
Tuesday saw the completion of the fifth round of the talks, which are due to resume on 24 August.
The discussions are part of the AU's attempt to find African solutions to Africa's problems, the BBC's Anna Borzello in Abuja says.
DECLARATION OF PRINCIPLES
Justice and equality for all
Democracy and regional devolution
Equitable distribution of national wealth
AU chief mediator Salim Salim said the declaration would send a message for ending the conflict and the realisation of peace and stability in Darfur.
"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," he told the signatories.
"Some formidable challenges lie ahead," he added.
The head of the rebel Sudan Liberation Movement, Abdel Wahed Mohamed al-Nur, said the agreement marked "the beginning of the road to peace".
His group signed the agreement along with the Justice and Equality Movement.
Among the broad commitments agreed upon are the upholding of democracy, the independence of the judiciary and "justice and equality for all, regardless of ethnicity, religion and gender".
The declaration also refers to "an effective devolution of powers" to regional authorities and the equitable distribution of national wealth.