It said his continued presence threatened any resolution of the crisis in the country, and that Libyans should be allowed to determine their future.

The call came in a final statement read out by Qatar's prime minister at a summit on Libya in Doha.

Rebels seeking to topple Col Gaddafi made their first high-profile diplomatic appearance at the summit.

The contact group also agreed to continue to provide the rebels with "material support" - a form of words described as ambiguous by the BBC's Jon Leyne - and also to consider channelling funds to them.

Earlier, delegates were told by UN Secretary General Ban Ki-moon that more than half of Libya's population of six million might eventually require humanitarian aid.

US Secretary of State Hillary Clinton has spoken of reports of "renewed atrocities" by pro-Gaddafi forces against civilians in Misrata. The US condemned the "brutal attacks", and was gathering information to "ensure that those who committed these atrocities are held accountable for their actions", she said.

Ahead of the meeting, the French and British foreign ministers said Nato should be doing more to support Western-led military operations against Col Gaddafi's forces amid suggestions that there were insufficient aircraft being deployed. The Pentagon clarified on Wednesday that US jets were still carrying out bombing raids on Libya's air defences.