The group normally produces the energy equivalent of 280,000 barrels of oil a day, a major part of it as natural gas, but "at the moment it is producing around 120,000 barrels a day, chief executive Paolo Scaroni told reporters on the margins of a parliamentary hearing in Rome.

Scaroni added that it was "difficult to say" when production would resume at normal levels, although some wells were still pumping in the west of the country, where Libyan leader Moamer Kadhafi still holds sway.

ENI, which has already repatriated most of its personnel in the troubled country, did not give details on what precise areas of production had been shut down.

On Tuesday the company announced that natural gas supplies from the turmoil-hit North African state through the Greenstream pipeline, the only gas link between Libya and Italy, and therefore Europe, had been suspended.

Several other oil companies have announced similar problems, with staff being evacuated and those remaining concentrating on security rather than production.

Some, such as Germany's Wintershall, France's Total and Spain's Repsol have suspended production altogether.

ENI has been operating in Libya since 1959. Last year it pumped the equivalent of 244,000 barrels of oil per day.

Eastern Libya was in full revolt on Thursday as veteran strongman Kadhafi clung to power, prompting a desperate expatriate exodus.

Thousands scrambled to flee what former colonial ruler Italy said was a "bloodbath" of hundreds of protesters in the oil-rich North African state, parts of which have fallen to opposition control and others into lawlessness.