By Svetlana Kovalyova
MILAN (Reuters) - Libya's leading foreign oil producer, Eni <ENI.MI> of Italy led the charge back into Libya on Monday as rebels swept into the Libyan capital Tripoli hailing the end of Muammar Gaddafi's rule.
Gaddafi's fall will reopen the doors to Africa's largest oil reserves with new players such as Qatar's national oil company and trading house Vitol set to compete with established European and U.S. companies.
Shares in European companies Italy's Eni <ENI.MI>, Austria's OMV <OMVV.VI> and France's Total <TOTF.PA> rose by 3-5 percent despite a $2 fall in the price of oil on hopes the firms would be able to quickly re-establish output from Libya.
Italy's Foreign Minister Franco Frattini said staff from Eni had arrived to look into a restart of oil facilities in the east of the country even as fighting between government troops and the rebels continued in Tripoli in the west.
"The facilities had been made by Italians, by (oil field services group) Saipem <SPMI.MI>, and therefore it is clear that Eni will play a No. 1 role in the future," Frattini told state
OPEC member Libya was producing about 2 percent of global oil output or 1.6 million barrels per day before the war and has reserves to sustain that levels of production for 80 years.
OMV said it was not in any talks yet.
"We are observing the current situation and further developments very closely. At the moment we are not holding any bilateral talks with the (National) Transitional Council," an OMV spokesman said.
Other major player in pre-war Libya France's Total <TOTF.PA> and Germany's Wintershall declined comment.
Analysts and industry observers have said Eni and Total could emerge as the big winners in post-war Libya due to their countries' heavy support for the rebels.
Big support from Qatar as well as oil trader Vitol, neither producers in Libya before the war, may also guarantee a chunk of reserves and influence goes to new players.
"Qatar will be a big player, Vitol might be an important one. Shell <RDSa.L> is also looking to boost its role," said a Western risk consultant with knowledge of negotiations.
Most global oil majors have taken a much more cautious approach to events in Libya with BP <BP.L>, not yet a producer in Libya, saying it was planning to return to explore but giving no timeframe.
"We fully intend to return to Libya to fulfill our contract when conditions allow," said a spokesman for BP, which did not have production in Libya before the war.
U.S. companies such as Marathon <MRO.N>, ConocoPhillips <COP.N>, Hess <HES.N>, Occidental <OXY.N> have pulled out of Libya at the start of the year and have had little direct involvement in the events there since then.
"They are just sitting and waiting and trying to figure out who will run the place," said the risk consultant who is advising some U.S. firms on Libya.
(Additional reporting by Svetlana Kovalyova, Sarah Young, Emma Farge, Writing by Dmitry Zhdannikov, editing Richard Mably)