The Libyan National Oil Corporation has said it will resume exports from contested oil terminals in the east of the strife-hit country.
Forces loyal to Gen Khalifa Haftar have seized at least three terminals from a rival militia force allied to the UN-backed government in Tripoli.
Gen Haftar is allied to a rival government based in the east.
The oil company says it is assessing damage and that it will carry out repairs immediately.
The Tripoli government has called for urgent talks over the seizure.
Libya has been plagued by instability and infighting since the toppling of Colonel Muammar Gaddafi in 2011.
The seized oil ports at Ras Lanuf, al-Sidra and Zuitina lie between Tripoli and Tobruk, where the country’s two rival governments are based.
Gen Haftar is one of the most powerful military figures in Libya, who refuses to recognise the authority of the UN-backed Government of National Accord in the capital.
The speaker of the Tobruk parliament, Agila Saleh, said Gen Haftar had "liberated" the oil terminals from occupying forces.
Libya’s conflict has dramatically reduced the country’s lucrative oil exports.
In a statement, the National Oil Corporation said it currently produced 200,000 barrels a day, but now expected to produce almost four times as much by the end of the year.
The US, UK and several European countries issued a statement condemning the seizure of the oil terminals, calling on Gen Haftar to withdraw his forces.
The news comes on the same day as a committee of British MPs released a report criticising Britain’s intervention in Libya in 2011.
Since then, Libya has been largely controlled by thousands of local militias, loyal to one of three governing bodies - the UN-backed national government, the Tobruk parliament, or the Islamist parliament in Tripoli - as well as the encroaching so-called Islamic State group.
- General Khalifa Haftar retains the loyalty of much of Libya’s military