Force should be used to reopen Libya's oil ports which were seized by a group demanding greater autonomy for the country's eastern part, Libya's oil minister said on Saturday.

A mix of militias, tribesmen and political minorities demanding a greater share of Libya's oil wealth and more political power have shut most oil fields and ports, cutting oil output to around 250,000 barrels per day (bpd) from 1.4 million five months ago.

"The ports have been closed for five months, in my opinion force should be used to reopen them," Abdelbari al-Arusi told reporters on the sidelines of an Organization of Arab Petroleum Exporting Countries (OAPEC) meeting in Doha.

In October, Libya's government had promised oil sales would in future be properly accounted for, one of the demands of the group which has seized three eastern ports that previously accounted for around 600,000 bpd in exports.

Arusi added that Marsa al Hariga port was expected to resume operation in the near future. "We have a lot of storage facilities there and I expect that it will reopen soon," he said.

As Libya works towards restoring its oil production to 1.5 million bpd, it will have to restore its market presence compared with other OPEC members. "There is concern over regaining our market share," Arusi said.

Gulf states led by Saudi Arabia lifted their output to make up for shortages over the past few years and have shown no sign of scaling back, as the group's target was left unchanged during its last meeting this month.

Iraq, Opec's second-biggest producer, has also been looking to boost its production following decades of war and sanctions.

However, Iraq's oil minister seemed less concerned about finding buyers for its crude amid increased supply from Gulf states.

"We are not concerned at all because currently what is being supplied is more or less equal to demand and next year we are expecting an increase in demand," Abdul Kareem al-Luaibi told reporters.

Iraq's output has struggled to exceed 3 million bpd on a sustained basis, compared with its end-2013 target of 3.5 million.

Luaibi's comments were echoed by Kuwait's oil minister Mustapha al-Shamali. "There is enough space for everyone in the market for the coming six months, then Opec will meet again and decide what to do," said Shamali.

Oil prices rose on Friday, fueled by spread trading and supply concerns. Brent crude gained $1.48 to settle at $111.77 a barrel, while US oil settled up 28 cents at $99.32 a barrel.-Reuters