Germany's Wintershall is the latest firm to have sent a small group of Libyan workers to a cluster of oil fields, where sites jointly operated by US firm Occidental Petroleum Corp and Canada's Suncor Energy Inc are also in the process of restarting.

With Libya's prized crude pumping through the desert to the coastal terminal of Ras Lanuf, workers say the country's largest refinery could restart within days, with around 300,000 barrels of oil from stocks already built up in tanks there.

Workers have been flown in on cargo flights but many pilots are nervous to cross Libya's skies that are still subject to a NATO-enforced no-fly zone.

Yet, hopes are high for a quick recovery.

"We are preparing to bring back all employees, nothing here has been damaged," said Amal field general manager Saad Ali Eshiem.

But fears of an attack loom large and many Libyans are reluctant to leave the safety of their hometowns for remote sites southeast of Sirte, where fighting continues, and few foreign workers have returned.

With sites operating with a fraction of their pre-war workforces, small teams onsite say output will at best reach 50 percent of total capacity without the help of their colleagues.

Oil flows will also depend on the condition of wells and pipes that have not been used for eight or nine months.

Foreign companies contacted by Reuters declined to say when they would redeploy workers to the fields near Jakhira.

Canada's Suncor said last week it was too early to comment on operations at its Amal field, jointly owned with Benghazi-based Agoco, while Occidental declined to comment on its 70,000 bpd Nafoora field also restarting in the area.

Copyright Reuters, 2011