Oil topped $110 a barrel for the first time since 2008 because of the disruption, even though Saudi Arabia has said other members of the Organization of the Petroleum Exporting Countries would be ready to meet any shortages.

Austria’s OMV said on Wednesday it might be heading for a full production shutdown in Libya. Total, Repsol, Eni and BASF have also said they are either slowing or stopping output.

The latest comments point to a growing impact on oil output from Libya, which produces 1.6 million barrels per day (bpd) of high-quality oil, or almost 2 percent of world output. About 1.3 million bpd is exported, mainly to Europe.

“We are evaluating the situation. We cannot say at the moment how production is developing exactly,” OMV chief executive Wolfgang Ruttenstorfer said.

“It is going down sharply. We do not rule out that it could come to a complete stop for a period of time.”

The figures given by oil companies and industry sources so far indicate that some 400,000 bpd of Libyan output — a quarter of the total — has been stopped, according to Reuters calculations.

The total is probably higher since it excludes Italy’s Eni, which said on Tuesday it suspended “some” Libyan output without giving details. Libya provided Eni with oil production of 108,000 bpd in 2009, the latest data available.

Information on the country’s output can be conflicting as oil firms often speak of their share of production and do not give overall supply at fields they operate or participate in.

“We have started to suspend our production. It is still too early to estimate the impact on our production,” a spokeswoman for France’s Total said. Total gets 55,000 bpd from Libya.

Libyan oil officials could not be reached by phone to provide information on output and exports.

A Tripoli resident who visited the headquarters of the National Oil Corporation, Libya’s state oil firm, on Wednesday told Reuters some staff had not come in. “Not all the people who are employed there were at work,” the resident said. “I would say about 30 percent of the people had come to work. At 1:30 (1130 GMT), the people working there left, leaving behind only the security guards.”

Staff said Shokri Ghanem, head of the NOC and Libya’s top energy official, was in his office holding meetings.

Most of Libya’s oil production operations are in the east of the country south of Benghazi. That city and most of eastern Libya have not been under central control since an uprising last week against the rule of Libyan leader Muammar Qaddafi.

While lifting the price of oil, the Libyan production shutdowns weighed on the shares of some of the afflicted companies.

OMV tumbled five percent on the news in Libya, which provided the company with 33,000 barrels of oil equivalent per day of output in 2010, around a tenth of its total output.

Spain’s Repsol and Italy’s Eni said on Tuesday they had shut down Libyan production. BASF unit Wintershall said on Wednesday it had stopped as much as 100,000 bpd of output, having said on Monday it was preparing to do so.

Repsol said it had shut the El-Sharara oilfield, which an industry source said pumps about 200,000 bpd — a figure equal to 13 percent of the

country’s output.

Libyan export terminals that ship both crude and oil products have been disrupted but supplies have not stopped flowing.

At least three cargoes have left Libyan ports in the past 24 hours, trade and shipping sources said on Wednesday. One tanker carrying 600,000 barrels of crude oil had loaded from Es Sider, close to the major export terminal Ras Lanuf.