Libya's National Oil Corp. (NOC) declared force majeure on El Feel oil field from Sept. 2, it said in a statement on Monday.
The field, which has a capacity of 70,000 barrels per day, is operated by Mellitah Oil and Gas, which is a joint venture between NOC and Italy's Eni.
Oil exports at major Libyan ports were halted on Monday and production curtailed across the country, amid a standoff between rival political factions over control of the central bank and oil revenue.