Gas exports to Italy from the Mellitah complex in northwestern Libya have been suspended since Saturday following clashes between militias in the area, an official at the National Oil Corporation (NOC) said.
"Gas exports have been completely halted," Mustafa Sunalla, an NOC deputy chairman said on Sunday.
The firefight was said to have begun after an argument escalated between local former rebel fighters in the area and guards at Mellitah, a security source said.
Italian oil and gas giant ENI which operates Mellitah in a joint venture with NOC, said gas flows from the field had been halted for security reasons and said Italy's industry ministry had been alerted.
Sunalla said NOC, the Libyan prime minister's office and defence ministry were holding round the clock meetings to try to resolve the situation.
ENI's production at Mellitah is about 115,000 barrels of oil equivalent per day, an industry source said.
Mellitah supplies Italy with gas through Sicily through the Greenstream pipeline. Italy gets the majority of its gas from Algeria, Russia and Norway.