The Sudanese government and rebel leaders from Darfur have signed two accords aimed at ending the crisis after weeks of talks.
The peace protocols hope to ease tensions on the ground
In a security deal the government - under international pressure - accepted a ban on military flights over Darfur.
A separate agreement seeks to ease delivery of humanitarian aid to Darfur, where 70,000 have died since the conflict began.
Observers are describing the accords as a breakthrough.
The move comes as aid agencies say the deteriorating security is hampering aid efforts.
"It is really a historical moment," Sudanese government spokesman Ibrahim Mohammed Ibrahim is quoted by Associated Press as saying after both sides signed the protocols.
Observers see the accords as a breakthrough, which came after two weeks of a second round of African Union (AU)-sponsored talks, between the government and the two rebel movements.
"We hope this will be the first stage toward the improvement of the situation on the ground," Ahmed Hussein Adam from the rebel Justice and Equality Movement (Jem) group said.
Nigerian President Olusegun Obasanjo, the current AU chairman, praised the accord as "a very important step in the right direction".
Last week the United Nations warned of anarchy in Darfur, where some 1.6 million people have fled their homes in the 21-month war.
Clashes between government and rebels mean large pockets of Darfur are now "no-go areas" preventing the distribution of food to nearly 200,000 refugees, the World Food Programme says.
But Sudan Humanitarian Affairs Minister Ibrahim Mahmoud Hamid says the situation on the ground is being overplayed by the international community.
"We have more than 270,000 who have gone back to their houses.
"We think that this is a good sign and indicator for the improvement of the situation in Darfur," he told reporters in Nairobi on Tuesday.
Meanwhile, the UN's Sudan envoy Jan Pronk has said the forcible relocation of more than 30,000 refugees from camps by security forces near Nyala last week was a breach of international law.
The government want to move inhabitants out of camps near towns
He told the BBC there was clear evidence of a criminal act at a camp, where women say they were beaten and raped.
The UN was trying to find out whether the forced relocation had been authorised by the government in Khartoum or whether it had been ordered by over-zealous local officials, Mr Pronk said.
The US government has also voiced its disapproval to the Khartoum government about the operation.
UN officials arrived in Sudan on Monday to probe genocide allegations, a term used by US Secretary of State Colin Powell in September to describe the killings in Darfur.
Pro-government Janjaweed militias are accused of driving the region's black Africans from their villages, since two rebel groups began an uprising in February 2003.