The centrepiece of the upcoming week's efforts will be a major conference of "friends of Libya" on Thursday in Paris, but the talking began on Thursday in Istanbul and continues at the United Nations in New York.

At stake is the credibility of the new rebel regime in Tripoli, which is taking charge of the country after overthrowing Moamer Qadhafi, whose brutal rule locked Libya in what one Tripoli imam dubbed a "42-year coma".

In order to quickly put in place a stable government and fill the dangerous vacuum left behind by the dictator whose portrait once beamed down from almost every wall in Libya, the National Transitional Council needs cash.

To get it, it is relying on its foreign friends -- led by Britain, France and the United States -- to unblock the tens of billions of dollars in assets once controlled abroad by the ousted regime and now frozen by UN decree.

These funds have not begun to flow, and on Thursday some 50 countries have been invited to Paris to discuss other practical steps such as donor funding, food and fuel supplies, police training and diplomatic recognition.

"This time you will see the new Libyan government front and centre of the meeting and this will be their kind of welcoming back into the fold and then setting the terms," a senior British official said.

Briefing reporters in London, he said NTC leaders would set out "how they envisage taking Libya forward and their plans, and also the kind of support they'd like from the international community."

His comments were echoed by a French official involved in planning the Paris talks, who said: "We're entering a new era, one of rebuilding. The NTC has announced the timetable. We'll be there to support them."

With events happening so fast, Thursday's guest list is not finalised. France's President Nicolas Sarkozy and Britain's Prime Minister David Cameron will host the talks, and UN Secretary General Ban Ki-moon will attend.

Canada's Prime Minister Stephen Harper has announced he will come, and the United States will be represented by a senior figure.

French officials said they had invited the president and the prime minister of the NTC, Mustafa Abdel Jalil and Mahmud Jibril, and hope both will attend, despite the challenges facing them in Tripoli.

"There will be high expectations after the collapse of the regime," Jibril warned Friday in Istanbul. "The frozen assets must be released for the success of the new government to be established after the Qadhafi regime."

Meeting in New York at the United Nations, western diplomats succeeded in unblocking 1.5 billion dollars in Libyan cash frozen in US accounts, a partial success they hope to repeat for bigger sums in the days and weeks to come.

French officials said they had chosen the piecemeal approach of working through the UN sanctions committee rather than seeking a US Security Council resolution to simply unfreeze all Libyan funds for "pragmatic" reasons.

South Africa has been reluctant to recognise the NTC while parts of Libya are still loyal to the former strongman, and sits on the Security Council.

In addition, the sanctions were authorised by UN Resolution 1973, which also gave the green light to the Nato-led military air operation that halted Qadhafi's advance and gave the rebels the advantage on the battlefield.

With fighting still raging and Qadhafi still on the run, the Allies are in no hurry to reopen debate on the resolution. "NATO is still mobilised and it's not time to drop our guard," a diplomat said.

In Istanbul on Thursday, the 28 countries and seven international bodies of the "Libya Contact Group" took measures to unblock around 2.5 billion dollars in funds. The rebels say they need five billion urgently.

Qadhafi's money was spread across the world, in accounts and investments. Some 37 billion dollars have been frozen in the United States, 12 billion pounds in Britain and "several billion euros" in France.

Tripoli is running out of water and the humanitarian situation in Libya is precarious. Jibril said he needed money for health care, government running costs and to "build a national army and a powerful police force."

UN chief Ban has proposed sending an international police force to help the NTC re-establish the rule of law, and is expected to discuss this with Abdel Jalil on Thursday in Paris.

The biggest question mark hangs over the attitude of the major non-Western powers -- China, India, Russia and Brazil -- who had concerns over the Nato intervention, but will now be asked to help in rebuilding.

They have been invited to Thursday's conference and China has said it will "consider this invitation in a welcoming spirit", which French diplomats take as a positive sign.