Haftar hands oil ports to unrecognised eastern authority
The strongman's announcement came just hours after his Libyan National Army said it had driven a rival militia out of the country's oil crescent and regained "full control" of the area.
Libya has been wracked by chaos since the 2011 armed uprising that toppled and killed long-time dictator Moamer Kadhafi, with two rival authorities vying for control.
Haftar supports an administration based in the east of the country.
A UN-backed unity government based in Tripoli has struggled to assert its authority outside the west.
"All the oil installations controlled by Libyan National Army are being handed over to the National Oil Corporation dependent on the provisional eastern government and that is headed by Faraj al-Hassi," Haftar's spokesman Ahmad al-Mesmari said.
The LNA announced last Thursday it had recaptured the Ras Lanuf and Al-Sidra terminals, a week after they were seized by armed groups led by militia leader Ibrahim Jadhran, but said operations in the area were unfinished.
On Monday, LNA spokesman Khalifa al-Abidi said "mopping up operations for enemy holdouts" had been completed.
Medics have said 16 LNA members were killed in the clashes, with the number of dead among Jadhran's forces unknown.
Jadhran's Petroleum Facilities Guard controlled the two key oil ports for years following Kadhafi's 2011 NATO-backed ouster - but they were eventually forced out by the LNA in September 2016.
'Anything is possible'
Mesmari, Haftar's spokesman, said oil revenues from the four terminals now under LNA control would be handled by the administration in the east supported by Haftar.
"No tanker will be allowed to dock in eastern ports without permission from the NOC" based in Benghazi, he said.
Mesmari did not mention whether Libya's eastern administration had found any buyers.
"Sales will be very difficult," said Libya analyst Jalel Harchaoui, adding that "anything is possible" if traditional Haftar allies like the United Arab Emirates stand by him.
In April 2016 Libya's eastern administration tried to "bypass Tripoli and sell 300,000 barrels independently - to no avail. The Libyan representative to the UN and the Security Council had the cargo stopped," Harchaoui said.
The Crisis Group's senior Libya analyst Claudia Gazzini said in a tweet the "LNA decision not to hand over Libya's key oil exporting terminals to NOC in Tripoli is dangerous. Could re-ignite war and deepen East vs West divide."
Haftar made the decision to transfer control of the terminals after realising "rival armed groups are financed by oil revenues secured by the LNA", Mesmari said, referring to Jadhran's forces.
Up until now, the terminals have been managed by the National Oil Company tied to Libya's internationally recognised government based in Tripoli.
The NOC is chaired by Mustafa Sanalla, who represented Libya last week at an OPEC meeting in Vienna.
Clashes between Jadhran's forces and the LNA in the oil crescent pushed the NOC on June 14 to suspend exports from terminals in the area, warning of billions of dollars in losses.
After visiting the Ras Lanuf terminal on Sunday, the NOC said violence had slashed oil production by almost half and cost billions of dollars in losses.
Harchaoui, the analyst, said Haftar's decision was a "surprise".
"Only a few days ago Haftar was trying to speak like a national figure... today we are witnessing the opposite," he said.
"Haftar is showing his other face, that of a leader who failed to impose himself as a political or military reality outside of Cyrenaica (Libya's eastern half) explicitly saying for the first time he wants to break the centralised oil revenue scheme in Tripoli".
Libya's economy relies heavily on oil, with production at 1.6 million barrels per day under Ghaddafi.
Ghaddafi's 2011 ouster saw production fall to about 20 percent of that level, before recovering to more than one million barrels per day by the end of 2017.