Sudan has agreed in principle to allow a joint United Nations and African Union peacekeeping force into Darfur, UN chief Kofi Annan has said.
The conflict has killed or displaced hundreds of thousands of people
Khartoum has previously refused a UN presence in Darfur. Under the plan, UN troops would reinforce AU peacekeepers, leading to a hybrid force.
However, Sudanese officials have not yet publicly responded to the proposals and the force's size has not been set.
More than 200,000 people have died in three years of conflict in Darfur.
The Sudanese government's opposition to a UN presence of any description in Darfur has so far been unwavering.
But diplomats say Sudanese President Omar al-Bashir has indicated in private that he might accept the proposals.
Mr Annan told reporters: "It is agreed in principle that, pending clarification of the size of the force, we should be able to take it forward."
UN'S THREE-STEP DARFUR PLAN
1) AU $21m support package
2) Deploy several hundred soldiers and police
3) Hybrid force with substantial UN command and control
Following the meeting in the Ethiopian capital, Addis Ababa, Sudanese diplomats are consulting with their government before commenting on the proposed compromise.
Mr Annan wants first to reinforce the existing AU contingent, which has been under-resourced and ineffective, by supplying extra money, troops and equipment.
The UN would then deploy several hundred soldiers and police officers to help the 7,000 AU troops in Sudan.
The third step is an AU-UN hybrid peacekeeping force.
African troops would get UN logistical support and there would be substantial UN involvement in the command and control of the peacekeepers.
The Sudanese government has been strongly resisting the idea that the UN take over control of the mission, but it is one of a number of conditions that must be met if the agreement hammered out in the Ethiopian capital is to be implemented.
There must be a ceasefire between Sudanese troops and rebel movements in Darfur. Attempts must be made to include rebel groups who did not sign a truce with the government in May.
The Sudanese government must also accept a substantially larger peacekeeping force than it wants - 17,000 troops rather than 12,000, reports the BBC's Adam Mynott in Addis Ababa.
Sudan's government says the scale of the problems in Darfur is being exaggerated for political reasons.
It claims it is disarming Arab militias, known as Janjaweed, who have been accused of carrying out genocide on its behalf.
Kofi Annan wants to reinforce the existing AU force with UN troops
But Sudanese troops and rebel movements have intensified fighting recently.
Two million people have been driven from their homes into camps where they face the constant threat of violent death, rape, hunger and degradation.
In Darfur itself, for the first time UN emergency relief coordinator Jan Egeland has been unable to get into camps because the security situation has become so poor.
The BBC's Karen Allen in El Geneina in west Darfur, says the mood is tense, with banditry and attacks on humanitarian staff and African Union forces making access increasingly difficult.
She says the camps, meant to be offering shelter to tens of thousands of displaced people, are now teeming with armed groups.
She adds that just 25km (16 miles) away from the border with Chad, the situation is worsening.
Neighbouring Chad has declared a state of emergency after the violence in Darfur spilled over the border.