Ben Ammar announced Tunisia's withdrawal from the 2010 race

Their withdrawal leaves four nations - South Africa, Morocco, Egypt and Libya - left in the running.

Tunisia were one of five African nations making their final presentations to Fifa's 24-man executive committee on Friday and their delegation were due to be the second country to present their credentials after Morocco.

But instead of extolling his country's virtues, Tunisia Football Federation president Hamouda Ben Ammar told Fifa that his country wanted to co-host the 2010 finals with neighbours Libya.

However, as Fifa had already insisted that there would be no co-hosting, they had no choice but to withdraw.

"We accept our candidacy can no longer exist," said Ben Ammar.

"We have taken stock of the decision by the honorable executive committee which once more confirmed that the World Cup will be organized by a single federation and therefore the idea of co-hosting this competition cannot be taken into account," he said .

Fifa president Sepp Blatter praised the Tunisian's decision.

"This is fair play, there's no provision in the Fifa statutes for co-hosting and I thank the Tunisians for their interest in the World Cup," he said.

Tunisia were ranked as outsiders along with Libya to stage the finals.

Tunisia's withdrawal is likely to benefit Morocco's bid to win the right to stage the finals.

Tunisia have one vote on the executive through member Slim Aloulou and he is now likely to switch his allegiance to fellow north Africans Morocco when the executive committee make their decision on Saturday morning.

Morocco's presentation broke with tradition as it included overseas personalities rather than just nationals from the bidding country.