Libya's eastern state oil firm AGOCO, which runs the Hariga port and the country's biggest oilfield, Sarir, produced 225,000 barrels per day (bpd) of crude in August, a company spokesman said.
The figure is in line with previous statements by Arabian Gulf Oil Co (AGOCO). The Nafoura and Bayda oilfields remained closed due to power cuts or protests, the spokesman said.
A tanker is lifting 1 million barrels of crude at Hariga, another energy official said. Hariga, located in Tobruk near the border with Egypt, is working normally despite a small oil spill outside the port, the official said, asking not to be identified. The spill could come from a tanker, he added.
The AGOCO spokesman said the source of the spill was unknown, adding that it amounted only to two barrels.
Hariga is Libya's main oil export port as the North African country slides deeper into conflict, with rival factions battling for control of its oil wealth.
Oilfields in the west and the eastern oil ports of Zueitina, Es Sider and Ras Lanuf remain closed due to the turmoil.
Oil output has fallen to less than 400,000 bpd, a quarter of what the OPEC producer pumped before an uprising toppled leader Muammar Gaddafi in 2011 and sent Libya into turmoil.
The Es Sider and Ras Lanuf terminals, the country's biggest, closed in December because of fighting between rival factions allied to Libya's two governments. Attacks by Islamic State militants have made it impossible to reopen fields connected to the two ports.
The western El Sharara and El Feel oilfields are still closed due to protests despite efforts by tribal leaders to reopen them, a member of the protesters said.
The two fields, which used to produce around 400,000 barrels a day, have been closed for months due to pipeline blockades and a strike by oil security guards.