Sun Air Executive Director Murtada Hassan said officials at the airport in Kufra, Libya, informed him of the surrender. He said there were only two hijackers but others may have slipped out with passengers released earlier. The number of hijackers and their identities has been unclear.
Hijackers commandeered the Boeing 737 jetliner, which was carrying 95 passengers and crew, soon after it took off Tuesday from the southern Darfur town of Nyala.
The plane, which had been en route to the Sudanese capital of Khartoum, was diverted to a World War II-era airstrip in Libya's Sahara desert oasis of Kufra.
Libya's official JANA news agency said earlier that negotiations between Libyan civil aviation authorities and the hijackers resulted in the release of all passengers. The agency reported that there were 87 passengers and eight crew members.
Earlier Wednesday, Kufra airport director Khaled Sasiya spoke to one of the hijackers, who demanded maps to fly to Paris and fuel for the plane, JANA reported.
Sasiya said the man, who identified himself as Yassin, told him that he and his fellow hijackers were from the Darfur rebel Sudan Liberation Movement led by Abdel Wahid Nur, according to the news agency's report.
SLM-Nour spokesman Yahia Bolad denied any involvement, saying his group has "no relation to this act."
Asked if French authorities could accept the hijackers arriving in France, French Foreign Minister Bernard Kouchner told Europe-1 radio that he could "not say anything now. But we are considering everything so that the passengers, the 100 passengers, are protected."
Kouchner also said that rebel leader Abdel Wahid Nur, who lives in Paris, denied he was in contact with the hijackers.
"He says he doesn't know these people and that he absolutely refuses to use such methods," Kouchner said. "It's not his way. He's rather a peaceful man."
The hijacked airliner belongs to a private company, Sun Air, the Sudanese civil aviation authority said in a statement carried by the Sudan Media Center, which has close links to the government.
Among the passengers were former rebels who have become members of the Darfur Transitional Authority, an interim government body responsible for implementing a peace agreement reached in 2006 between the government and one of the rebel factions, a security official at Nyala airport said. He spoke on condition of anonymity because he was not authorized to talk to the press.
Sudan's consul in Kufra, Mohammed al-Bila Othman, told SUNA there were some 500 security and police personnel at the airport as well as ambulances and firefighting vehicles.
The chief of police of the southern Darfur province, Maj. Gen. Fathul-Rahamn Othman, told SUNA that the hijacking was meant to "destabilize security and is part of the events taking part in the Darfur provinces."
Darfur's ethnic African rebels have been battling the Arab-led Khartoum government since 2003 in a conflict that the U.N. says has killed up to 300,000 people and driven 2.5 million from their homes.
In the worst attack in months, the Sudanese military on Monday assaulted the Darfur refugee camp of Kalma, near Nyala airport, from where the hijacked plane took off.
A spokesman for Darfur's U.N.-African Union peacekeepers, Nourredine Mezni, said at least 33 people killed in the attack were buried Tuesday, though some U.N. officials said the toll could be higher.
A spokesman for one of the rebel groups, the Justice and Equality Movement, Ahmed Hussain, said he had reports of 70 dead. He accused the government in the hijacking, saying it was trying to "divert attention" from Monday's attack.