Tripoli (AFP) - Forces opposed to Libya's unity government handed management of four vital oil ports to the National Oil Company on Wednesday after seizing them in a blow to fragile peace efforts.
Prime minister-designate Fayez al-Sarraj called for urgent talks after the ports were captured by forces loyal to Field Marshal Khalifa Haftar, who supports a rival administration in the country's east.
The offensive in the so-called oil crescent was a major setback for Sarraj's UN-backed Government of National Accord, which is almost entirely dependent on oil revenues for its income.
Libya, which has Africa's largest oil reserves, has only managed to export a few tankers of crude in recent months, with efforts to revive the industry thwarted by jihadist attacks and political turmoil.
Haftar's seizure of the ports raises the prospect of renewed oil exports from Libya, whose crude reserves are estimated at around 48 billion barrels.
"Today the ports of Zuwaytina, Brega, Ras Lanuf and Al-Sidra were handed over to the National Oil Company," said Colonel Ahmad Mesmari, a spokesman for Haftar.
"The entire oil crescent is under the NOC's administration," he told AFP, adding that a force under Haftar's control would continue to guard the ports.
The NOC in Tripoli said in a statement on Tuesday night that it planned to resume oil exports from the ports "as soon as possible".
The fighting between the two sides -- the first since the unity government started work in Tripoli in March -- was the latest escalation of the chaos that has gripped Libya since the overthrow of Moamer Kadhafi in 2011.
- 'Turning point' -
Sarraj has said Libya was at a "turning point" after the assault on the oil ports with its future as a united nation in serious question.
"I call on all sides to halt provocative actions and sit down urgently at the same table to discuss a mechanism that would enable us to get out of this crisis and put a stop to the conflict," he said.
UN envoy Martin Kobler, who has appealed repeatedly for a halt to the offensive, was to brief the Security Council on the crisis later on Wednesday.
The unity government is key to UN efforts to restore stability to Libya and it now faces an even tougher battle to assert its authority over the rival administration in the east.
The capture of the oil crescent means the rival administration now controls virtually all of the eastern Cyrenaica region.
The NOC, which said that it recognised the GNA, did not explain how it could export oil from ports controlled by Haftar's forces.
"Our technical teams already started assessing what needs to be done to... restart exports as soon as possible," said NOC chairman Mustafa Sanalla, who visited Zuwaytina port on Wednesday.
He said he hoped for "a new phase of cooperation and coexistence between Libya's factions, as well as an end to the use of the blockade as a political tactic".
- 'Inflammatory' move -
Haftar, 73, who sees himself as Libya's saviour after driving jihadists out of most of the main eastern city of Benghazi, is the most powerful backer of the eastern administration.
The head of the eastern parliament, Aguila Saleh, on Wednesday promoted Haftar from the rank of general to field marshal, the legislature said in a statement.
Meanwhile, the writ of Sarraj's government is confined to the western Tripolitania region where its forces have been battling jihadists of the Islamic State group in the coastal city of Sirte for months.
Western governments have voiced serious concern that Libya's deepening divisions play into the hands of the jihadists' efforts to establish a base just across the Mediterranean from Europe.
The United States and its European allies issued a joint statement condemning Haftar's offensive and calling for the return of the oil ports to unity government control.
Claudia Gazzini, a Libya analyst at the International Crisis Group, warned Haftar's move was "inflammatory" and could provoke a military response from the GNA.
"From a political and military point of view, these developments are a huge setback to the authority of the UN-backed fledgling government in Tripoli," she said in a report.
But she said while some in the GNA were pushing for military action to retake the terminals, any such attempt could be "disastrous".
"A first urgent step would need to be to de-escalate current tensions and avoid a renewed flare-up," she said.