The move follows a decision by the UN Security Council to authorize a no-fly zone over Libya and expand sanctions against Muammar Qaddafi and his close allies that were first imposed in February.

In addition to the UN measures, the European Union has also imposed a series of further sanctions over the past month against Qaddafi and companies associated with him or his inner circle.

The list so far has included more than 30 people and groups, such as Libya’s central bank and the $70 billion Libyan Investment Authority. Germany has pushed for the inclusion of energy firms, but Italy has until now opposed this.

“The sanctions were adopted,” said one EU diplomat.

However, the impact of an oil embargo against Libya is likely to be limited because the country’s oil industry has been brought to a standstill by heavy fighting between rebels and the government of Qaddafi.

Libya had been producing 1.6 million barrels per day.