"We have reason to believe that the majority of the oil and gas fields … are no longer under Gadhafi's control," Oettinger told a news conference after a meeting of EU energy ministers.
Instead, regional tribes and opposition leaders have taken over. That's why sanctions targeting the oil and gas sector might not make sense, Oettinger said.
"We might potentially be punishing the wrong people," he said Monday in Brussels, shortly after the European Union had slapped a package of diplomatic sanctions on the inner circle of the Libyan regime following the bloody crackdown on protesters there.
Over the past days, the crisis in Libya and similar protests elsewhere in North Africa and the Middle East had pushed oil prices to nearly $120 a barrel. Most of the Libyan oil is exported to refineries in Italy, France and Germany.
Oil production had ground to a halt in Libya amid the unrest but is apparently "about to start again," Oettinger said.
Gas and oil from Libya, the Organization of Petroleum Exporting Countries' fourth-largest producer of crude, account for around 3 percent and 10 percent, respectively, of EU imports. They're "not insignificant but they're also not huge," Oettinger said.
Individual countries are affected to a much greater degree than others, however.
Italy, for example, imports 376,000 barrels of Libyan crude a day -- more than one-fifth of the country's overall demand -- figures from the International Energy Agency indicate.
Spain has reduced the maximum speed limit by 6 miles per hour in a bid to save fuel. A country reeling from the economic crisis, Spain is highly dependent on oil imports.
Oettinger said people in Europe needn't fear a new oil crisis, however.
"We have significant oil reserves within the European Union, so our oil companies are in a position to make up for some percent of crude not delivered," Oettinger said. "We also know that the OPEC states and other partners such as Russia are willing to compensate for the hold-up in supplies."
The largest producer in OPEC, Saudi Arabia has already said it was ready to step in for supply losses from Libya.
If the unrest doesn't spread, the oil price will likely reach a peak over the next days and then drop, Oettinger said.