The UN Security Council has ordered the assets of two Libyan banks that had been under the control of Muammar Gaddafi to be unfrozen, clearing the way for the return of more than 40 billion US dollars (£25 billion) to help the new government rebuild the country.
The transitional government had asked the council's committee monitoring sanctions against Libya to lift the asset freeze on the Central Bank of Libya and its subsidiary, the Libyan Foreign Bank.
There were no objections from any of the 15 council nations who comprise the committee by the deadline on Friday evening so the sanctions were immediately lifted.
Soon after, the US government announced that it had rolled back most sanctions against Libya's banks, unblocking more than 30 billion dollars (£19 billion) in assets.
UK Foreign Secretary William Hague also said his Government is seeking swift European Union action to pass the regulation required to release about £6.5 billion in assets frozen in Britain. Billions of dollars more in Libyan assets frozen elsewhere are also expected to be released.
The Security Council froze the assets of five key Libyan financial institutions in March following the uprising against Gaddafi's 42-year rule and his deadly crackdown on protesters.
After Gaddafi's death and the end of the eight-month civil war in October, the Security Council eased some financial restrictions to allow a resumption of trading, but the freeze on assets that the Central Bank and Foreign Bank held before March remained in place until Friday's delisting.
Mr Hague welcomed the sanctions committee's decision, saying: "Libya's government will now have full access to the significant funds needed to help rebuild the country, to underpin stability and to ensure that Libyans can make the transactions that are essential to everyday life. The transitional government must now redouble its efforts to build a transparent and accountable financial system which will underpin a newly prosperous Libya."
The White House said unfreezing the assets will give the Libyan government access to most of its worldwide holdings "and will help the new government oversee the country's transition and reconstruction in a responsible manner". The US is helping Libya with the technical steps to make the assets available as soon as possible, it said.
Libya is still subject to UN sanctions, including an arms embargo, and assets of the Gaddafi family and members of his regime remain frozen along with assets of several other financial institutions.