Libya's National Oil Corporation said will resume production within hours at the southwestern Sharara oil field.
This came after control was retaken from an armed group last month, the Associated Press (AP) reported.
The militia's blockade had cost the state oil company around $1.8 billion in lost production.
NOC chairman Mustafa Sanalla said on Tuesday that force majeure was lifted and that authorities "received assurances that site security has been restored" to control by local oil security forces. The NOC moved to reopen the facility late Monday.
Forces led by Libyan Libyan National Army (LNA) commander Khalifa Haftar Field captured the oil field from an armed militia in February.
