Libya's parallel government controlling the capital will take legal action against buyers of oil bypassing the Tripoli-based state oil firm National Oil Corporation (NOC), its oil ministry said.
In a growing confrontation for control of the North African state, Libya has two rival governments since a group called Libya Dawn took over the capital in the summer and set up its own alternative administration and parliament.
Three years after the fall of Muammar Gaddafi, oil is increasing at the centre of the confrontation between the self-declared Tripoli government and the internationally recognised government of Prime Minister Abdullah al-Thinni.
The statement from Tripoli was in response to Thinni's government appointing an alternative head of NOC in Tobruk in an apparent move to stop Libya Dawn's influence over the state oil company, which is based in the capital.
"We warn against dealing with any other body," the Tripoli government said, referring to Thinni's Tobruk appointment. "The NOC (in Tripoli) is the only executive body for the administration and investments in oil resources."
Thinni had originally confirmed NOC Chairman Mustafa Sanallah when it unveiled a new cabinet in September. But he is based in Tripoli.
Thinni government officials said new chairman was Al-Mabrook Bou Seif and said Sanallah was no longer NOC chairman. They said the appointment came after Tripoli's rival government appointed its own oil minister to work out of NOC headquarters.
The appointment and counter appointments have spread confusion over who is representing Libya at the OPEC meeting in Vienna and who is controlling the North African country's oil exports and revenue.
The rival oil minister Mashallah Zwai had told Reuters he would come to Vienna with a separate delegation. There was no immediate sign of Zwai at the meeting. He had said late on Tuesday that he was still waiting for an invitation and visa.
Thinni's deputy vice energy minister, Mohamed Oun, who was in Vienna, said his government wanted the United Nations and Western powers to help stop the rival government accessing the central bank funds from oil sales.
Oun reiterated that current oil production was at around 700,000 barrels per day. Libya's political conflict has started to hit production after clashes over the large El Sharara oilfield over recent weeks.
Libya's Nafoura oilfield will start pumping oil to ports from Friday, targeting an initial output of 20,000 barrels a day, a spokesman for the field operator said on Thursday.
The field, located in the east, restarted work this week after officials convinced local residents to end a protest aimed at demanding more jobs.
Libya is also starting preparations to restart the southwestern El Feel oilfield, an NOC spokesman said. The field had been closed earlier this month after clashes at the neighbouring El Sharara. Both fields use the same power supply.
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