Libyan state oil firm NOC will reopen the Sharara oilfield, the country's biggest, only after an inspection to establish security, a spokesman said on Tuesday.
The comments came shortly after officials for Libyan National Army forces said they handed over control of the field to an oil facilities guard to encourage NOC to restart production that has been halted since December.
Control over the oilfield has been claimed by different forces since tribesmen and state guards seized it in December, making financial and other demands. NOC declared force majeure, a waiver on its contracts.
"NOC has sent an inspection team to assess security at Sharara and to verify that all armed militia have left the field prior to force majeure being lifted," the spokesman said by text message.
A no-fly zone imposed by the Libyan National Army meant this could take some days, he said, adding that the zone indicated a "serious continuing threat level."
"We call on NOC to lift force majeure," said Naji al-Maghrabi, the eastern-based commander of the oil facilities guards appointed to protect the field, in a statement posted online.
A spokesman for the Libyan National Army confirmed the handing over of the field to the oil guard.
There was no immediate comment from NOC.
It was not immediately clear if handing over security to guards under the control of an eastern-based commander would meet NOC's demands.