Youcef Yousfi said Sonatrach's operations had stopped completely amid the fighting between rebels and forces loyal to Muammar Gaddafi, Kuwait's KUNA news agency reported on Sunday. Sonatrach does not produce oil or gas in Libya but operates several exploration blocks.

Oil output in OPEC-member Libya has fallen sharply due to the shutdown fields operated by foreign companies.

A Reuters survey estimated Libya produced 320,000 barrels per day (bpd) of crude in March, down from 1.6 million bpd before the crisis erupted.

Sonatrach operates three natural gas-focused exploration blocks and discovered oil at another block in the Ghadames Basin in 2009.

Sources told Reuters in February that Sonatrach had pulled out staff from the Ghadames region.

Yousfi told KUNA that the current crisis in Libya had not affected oil demand so far. He added that prices still remain at an "acceptable" level and there was no oil supply shortage.

Oil prices jumped on Friday as supportive U.S. jobs data reinforced economic growth expectations and Libya's conflict and Middle East unrest kept supply threats in focus, pushing both Brent and U.S. crude to their highest settlements since 2008.

Brent crude for May delivery rose $1.34 to settle at $118.70 a barrel, the highest close since August 2008 and up $3.11 for the week. It hit a contract high of $119.14 in post-settlement trading.