NATO decided to delay a formal decision to end Libyan air operations until Friday after Libya's new rulers asked for an extension and Russia demanded UN consultations, diplomats said.

In the wake of Muammar Gaddafi's death last week, NATO's decision-making body, the North Atlantic Council (NAC), had been expected to formally agree Wednesday to set October 31 as the date to end the seven-month-old air war.

"The NAC will meet with partners this Friday to discuss the Libya mission and take a formal decision," NATO spokeswoman Oana Lungescu told AFP.

NATO Secretary General Anders Fogh Rasmussen is continuing consultations with the United Nations and leaders of Libya's National Transitional Council, Lungescu said.

Alliance ambassadors took a preliminary decision last week to end the mission at the end of the month after Gaddafi was killed by NTC forces and the fallen dictator's loyalists lost the battle for his hometown of Sirte.

But Libyan interim leader Mustafa Abdel Jalil asked NATO on Wednesday to stay until the end of the year. Another top NTC official, finance minister Ali Tarhuni, said Tuesday he wanted the mission to last at least another month.

Lungescu, however, said she was unaware of any formal requests from the NTC. "To my knowledge there isn't a formal request," she said.

Diplomats said another reason for the delay was that Russia wants NATO to wait for more consultations at the United Nations Security Council.

"Russia wants the Security Council to debate the situation in Libya before the NATO meeting," one diplomat said.

Another diplomat said Russia wants a UN resolution calling for the end of the air operations, which were authorised by the world body in March.