The United Nations on Friday eased sanctions against Libya and gave the country's UN seat to the former rebel government which toppled Muammar Gaddafi and is still battling his forces.

Western nations who were at the forefront of the push for sanctions and help for the rebels battling Gaddafi, hailed the 'historic' double breakthrough for the interim government on the international stage.

The 15-member Security Council unanimously passed a resolution to ease an assets freeze and arms embargo against Libyan companies and the government. It maintained sanctions against Gaddafi and a no-fly zone which has been used to justify NATO air strikes against Gaddafi targets.

Security Council resolution 2009 also set up a UN mission to go to Libya to help the interim government to arrange elections and write a new constitution.

The measure eases sanctions against major enterprises such as Libyan National Oil Corporation, the central bank and the Libyan Investment Authority sovereign wealth fund in a bid to get the economy moving again.

The Security Council expressed concern at the "proliferation of arms in Libya and its potential impact on regional peace and security."

But the resolution allows arms supplies and technical assistance to the transitional government for the security of the authorities and for the protection of UN personnel, media and aid workers in the country.

The Security Council passed resolutions in February and March allowing for sanctions and measures to protect civilians, which NATO has used to justify its military strikes in Libya over the past six months.

While agreeing to keep the no-fly zone in place, Russia's UN envoy Vitaly Churkin demanded that it be quickly reviewed, renewing accusations that NATO has acted outside the UN resolutions.

The UN Support Mission in Libya, UNSMIL, would be set up for an initial three months to help in what diplomats insist is essentially a political operation.

It would give advice on restoring security but would concentrate on efforts to "undertake inclusive political dialogue, promote national reconciliation and embark upon the constitution-making and electoral process."

Earlier, the UN General Assembly voted by 114 countries to 17, with 15 abstentions, to let the interim government take up Libya's UN seat.

A group of Latin American countries, led by Venezuela, Cuba and Nicaragua, demanded the vote on the Libyan application. Some southern African nations wanted a decision postponed.

Venezuela's ambassador, Jorge Valero, called Libya's rebel leadership a group guided by the United States and NATO "which has no legal or moral authority."

But the UN vote allows interim government leader Mustafa Abdel Jalil to attend next week's UN gathering of world leaders in New York. Jalil is to meet US President Barack Obama and other key figures on the sidelines of the UN General Assembly.

About 90 countries now recognize the National Transitional Council, whose leaders moved to Tripoli this week.

Libya has had no official UN representative since March, when Gaddafi withdrew the credentials of the ambassador, Abdulrahman Shalgham, his former foreign minister, who went over to the rebels.

"It is a very successful day for all the countries which have really contributed to the liberation of Libya from the dictatorship of Gaddafi," said France's UN ambassador Gerard Araud.

Ibrahim Dabbashi, who was deputy ambassador under Gaddafi but went over to the rebels after the strongman's crackdown on protests and is now representing the interim government, told the Security Council it had been a 'historic' day for Libya.