An estimated 2.5 million Darfuris have also been driven from their homes by militias armed and backed by the Sudanese government.
Weeks of discussions
Sudan's agreement paves the way for 38 UN observers to deploy by the end of the year and the rest of the 105 during January, Wednesday's statement said.
"We have agreed on three phases of support from the United Nations to the African Union ... financial, technical and personnel"
foreign ministry spokesman
"It was agreed that UN military and police officers will wear their national uniforms with a blue UN beret. In addition, they will wear an AU armband," the joint UN-AU statement said.
The UN will also provide $21 million to the African Union, including computers, communications equipment and water tankers.
"We have agreed on three phases of support from the United Nations to the African Union ... financial, technical and personnel," Sudanese foreign ministry spokesman Ali al-Sadig told a news conference in Khartoum.
Asked if there was agreement on a joint force, three government ministers at the news conference said: "No."
Al-Sadig said there was agreement on "a joint operation", making it clear any UN personnel in Darfur would be working on computers or advising rather than peace enforcing soldiers.
Sudan's government had previously refused to allow any UN forces in Darfur.
In a letter made public on Tuesday, Omar Hassan al-Bashir, the Sudanese president, told the UN he endorsed the joint AU-UN force, but said he wanted a veto over its implementation.
Despite an AU-mediated peace deal in May, violence has escalated in Darfur after rebel factions who reject the deal renewed hostilities with the government in June.
Lacking equipment, logistical experience and funds, the AU has failed to stem the clashes and its operations have been severely restricted by attacks on its personnel.
Mostly non-Arab rebels took up arms in Darfur in early 2003, accusing central government of marginalising the remote region on the border with Chad.
To quell the revolt, Khartoum armed militia, who now stand accused of a campaign of rape, murder and pillage that Washington calls genocide.
Khartoum denies genocide, but the International Criminal Court is investigating alleged war crimes in the region.