The request was made in a letter sent to the North Atlantic Treaty Organisation's Secretary-General Jaap de Hoop Scheffer by AU commission chairman Alpha Oumar Konare, said Nato spokesman James Appathurai on Wednesday.
After receiving the message at Nato's headquarters on Wednesday morning, de Hoop Scheffer informed the permanent representatives of Nato's members, who "agreed that exploratory talks should begin with the AU", Appathurai said.
The request comes ahead of a scheduled meeting on Thursday of senior AU diplomats in Ethiopian capital Addis Ababa to consider a significant expansion of the pan-African body's operation in Sudan's troubled western region of Darfur.
The AU's Peace and Security Council will discuss the possible expansion of the mission, perhaps by more than 100%, an official at the AU's headquarters in Addis Ababa said.
The letter called for "the AU Commission and Nato's general-secretariat to begin discussions on the possibility of Nato providing logistical support for the AU in Darfur", Appathurai said.
The AU commission chairman will
visit Nato headquarters in May
No date has been set for the talks to begin, but Konare is to visit Nato headquarters on 17 May, the spokesman said.
It was not immediately clear how Nato would help, but the alliance has large logistics, transport and planning capacities at its disposal.
"We are not talking about a significant Nato deployment to Africa," a Nato official clarified, but did rule out a small contingent being sent to the area.
Last week, US Secretary of State Condoleezza Rice said Nato should provide help to alleviate suffering in the Darfur region if the AU asked.
"If there is a request, I would hope that Nato would act favourably," Rice said last Thursday in Vilnius at the end of a Nato meeting.
French Foreign Minister Michel Barnier said at the time that Paris preferred the European Union playing a role in Darfur rather than Nato.
Condoleezza Rice wants Nato to
provide support in Darfur
The AU has about 2200 troops in Darfur protecting AU observers monitoring a shaky ceasefire between Khartoum, its proxy militias and two rebel groups that have been fighting the government for two years.
It plans to boost the size of its Darfur mission to 3320 by the end of May, but many have said the expansion should be larger.
Last month, UN humanitarian affairs chief Jan Egeland said there was an urgent need for the expansion to prevent the number of displaced Darfur residents from rising to 3 or 4 million from the current 2 million.
By some estimates, the conflict in Darfur has cost 300,000 lives since early 2003.