But the secretive process of choosing a successor to the British secretary-general, who is standing down at the end of this year, remains far from over, they added.

The civilian chief of the US-led alliance has traditionally come from a European country, but no one figure has yet emerged as a strong contender to replace Robertson.

Other names circulated have included Portugal's Antonio Vitorino, the European Commissioner for justice and home affairs, and Norwegian Defence Minister Kristin Krohn Devold.

But neither is thought to enjoy strong support in NATO, whose member states must agree unanimously on the next secretary-general.

Manley, who is also Canada's finance minister, last month withdrew his candidacy from the race to succeed retiring Prime Minister Jean Chretien, saying he did not have the support to beat front-runner Paul Martin.

His name surfaced in the NATO hunt in recent days during informal consultations among alliance members, the diplomats said.

But it would be premature to say the Canadian has emerged as a front-runner, said one diplomat.

"We're not yet in the final, really political phase of choosing," he said.

The debate will intensify when NATO defence ministers hold informal talks on October 8-9 in Colorado Springs, Colorado.

Robertson, 56, a former British defence minister, announced in January that he would be standing down after four years in the job.

WAR.WIRE