Libyan rebels occupying major oil ports in the east of the country said today they would not deal with new Prime Minister Ahmed Maiteeq, branding him "illegitimate".

Maiteeq's predecessor Abdullah al-Thinni had reached an agreement with the rebels to reopen four eastern oil ports, but so far only the smaller ones Hariga and Zueitina have been handed over to government forces.

Both sides had agreed to hold further talks over reopening the larger Ras Lanuf and Es Sider exports terminals. But the rebels' comments on Wednesday suggested those efforts could hit difficulties.

"Maiteeq came to power illegally," rebel spokesman Ali Hasi said, without elaborating.

Maiteeq was sworn on Sunday in after a chaotic election in parliament. Many deputies have challenged his appointment.

The North African country has been mired in turmoil since the 2011 overthrow of strongman Muammar Gaddafi. Its government and army has struggled to assert authority over a country still awash with arms and rival militias.

A wave of seizures of export ports and oilfields across the desert nation has cut oil output to 250,000 barrels a day, down from 1.4 million bpd in the summer.