Rebuilding Libya's infrastructure will take at least 10 years, according to the head of the Libyan Stabilisation Team at the country's National Transitional Council (NTC).
Libya's infrastructure was in a poor state even before the revolution due to "utter neglect", the head of the team, Ahmed Jehani, told the BBC.
The first priority must be to unfreeze Libyan assets held abroad, which total more than $100bn (£61bn), he said.
International help will also be needed.
Mr Jehani said in an interview with the BBC's Middle East Business Report: "Its going to be quite a while... it will be at least a decade because the infrastructure before was in utter neglect."
Production of oil, Libya's main export, has fallen from 1.6 million barrels a day before the conflict to fewer than 100,000.
Libya's NTC has already been outlining its strategy to stabilise the country once Colonel Gaddafi has gone.
Its main aim is to secure humanitarian aid for people affected by the fighting, and to get Libya's economy running again.
Mr Jehani said his stabilisation team would give priority to rebuilding the most war-damaged parts of the country, including Misrata and the Western Mountains.
He said outside help would be needed, but that any plan of action would be put before a parliament for approval.
"A lot of financial institutions have expressed their intentions and desires to help us and we will look at all of that.
"All of this will be put in front of the elected government to vote on and then our job will be finished."
Outside financial help is in the pipeline.
The United Nations Security Council, which had frozen Libya's overseas assets, has agreed to unfreeze $1.5bn for humanitarian needs.
A meeting of donor countries has been held in Doha, capital of Qatar, with a target of raising $2.5bn to pay the salaries of government workers as well as funding treatment for people injured in the fighting.