Al-Qadhafi has been asked by other African leaders to make contact with various parties in Darfur, western Sudan, to help solve the conflict there.
Idris Ibrahim Azraq, spokesman for the rebel Justice and Equality Movement (JEM), said Libya was host to a large number of Darfur migrants. Strong links had therefore already been forged.
Speaking of Libyan leader al-Qadhafi, he said on Monday: "We think he can play a vital role."
A representative of the other main Darfur rebel group, the Sudan Liberation Movement (SLM), also said al-Qadhafi could play a positive role.
The leaders of Sudan, Chad, Egypt and Nigeria met the Libyan leader on Sunday to discuss the conflict in western Sudan, which the United Nations says has killed 70,000 people and driven 1.45 million from their homes since it began in February 2003.
They commissioned al-Qadhafi to continue contacts with all
parties to the conflict until a solution is found.
Rebels accuse the Khartoum government of neglecting their
region, a vast area with scarce resources. They also say the
government has armed Janjawid tribesmen to attack villages and kill the inhabitants - a charge Khartoum denies.
The UN Security Council has threatened Sudan with possible
Around 1.5 million people were
uprooted in the conflict
sanctions if it does not end the violence in Darfur.
Rebels said Libya was a neutral player which could bring parties to the conflict closer. Tripoli's ties with its neighbours have often been volatile but it has also often sought to mediate African conflicts.
Rebels were more sceptical about the role Egypt and Chad could play, citing a bias from them in favour of Sudan.
JEM and the SLM were in Tripoli before the summit, but have yet to meet al-Qadhafi or hold high-level meetings with Libyan officials.
The five African leaders gave their support to African Union-sponsored peace talks due to resume in Abuja on Thursday after collapsing last month.
The leaders also said they welcomed Sudan's efforts to meet international commitments and hoped Sudan would continue with steps to fulfil UN resolutions.
"We think that [reducing pressure] is not the right approach to solve the problem. The government will not respond unless there is more pressure"
Idris Ibrahim Azraq,
spokesman for the rebel JEM
However, Nahar Usman, spokesman for the SLM, also in Tripoli, said: "Our position is that it [the summit] is a distraction from the real venue which is the AU and we think that is the place to deal with the Darfur problem right now."
The rebel spokesmen feared the summit might have been seeking to relieve the pressure on Sudan.
"We think that [reducing pressure] is not the right approach to solve the problem. The government will not respond unless there is more pressure," Azraq said.