A group of rebels ended an almost year-long blockage of the two eastern export terminals last week.
Last week, rebels agreed to allow the resumption of oil exports from the two major ports, ending an almost year-long blockade to press financial and political demands.
The state oil firm had declared force majeure, a waiver of contractual obligations, when the rebels seized the ports last year.
Ali Al-Ahrash, commander of the state Petroleum Facilities Guards (PFG) in charge of protecting oil facilities, said the ports were ready to resume exports.
"The situation at the two ports is safe and the National Oil Corp can resume work at Ras Lanuf and Es Sider," he told Reuters. "We officially notified them about this." Under Libyan rules the PFG force needs to notify NOC by letter that the ports are under full government control before exports can resume.
Disputes over Libya's vast oil resources have been among the many triggers for conflict between rival brigades of former rebels and allied political factions since civil war ended four decades of Muammar Gaddafi one-man rule in 2011. Port rebel leader Ibrahim Jathran had agreed in April to reopen two smaller eastern ports, Zueitina and Hariga, and then gradually free up Es Sider and Ras Lanuf.
After that deal, shipments from Zueitina were delayed because of damage from the blockade, while Hariga has seen only a few tanker loadings, hampered by a separate protest temporarily closing the port again.