By Laurent Prieur

NOUAKCHOTT (Reuters) - A Libyan delegation left Mauritania on Wednesday without Muammar Gaddafi's intelligence chief Abdullah al-Senussi, but the Libyan government spokesman said Senussi's extradition was expected soon.

Libya is vying with France and the Hague-based International Criminal Court (ICC) to try Gaddafi's former right-hand man, arrested on Friday when he flew in to the Mauritanian capital Nouakchott using a false passport.

Mauritanian sources played down Libyan suggestions that a deal to extradite Senussi was almost finalized and said other countries also had a say in the case.

"We have an assurance from Mauritania that it will extradite ... Senussi, but there are legal procedures which must be respected and we will wait," Libyan government spokesman Nasser al-Manee told reporters before boarding the plane.

"No date has been set for his physical extradition, but it will be soon," he added. A diplomatic source said the plane later took off as scheduled.

Libyan Deputy Prime Minister Mustafa Abu Shagour, leading the delegation, said after talks with Mauritanian President Mohamed Ould Abdel Aziz on Tuesday that Aziz had given his consent to Senussi's extradition, adding he would "soon be in a Libyan prison."

Mauritanian sources differed. "The principle of Senussi's extradition to Libya has been agreed," said a source close to the Mauritanian presidency. "What remain to be determined are details like the timing," the source added.

"It's not just Mauritania and Libya that can settle this," a Mauritanian security source said, adding that the West African state, a former French colony heavily dependent on foreign aid, acknowledged that other countries should also have a say in Senussi's fate.


The source declined to elaborate but several rights groups have said they doubt whether Senussi, 62, would have a fair trial in Libya and say he would be better transferred to the ICC to face charges of crimes against humanity.

Aziz, an army general who seized power in 2008 and won elections a year later decried by rivals as rigged, has enjoyed solid support from Paris that has helped him win international respectability and an IMF funding program.

France wants Senussi in connection with a 1989 airliner bombing over Niger in which 54 of its nationals died. A second Mauritanian security source told Reuters on Tuesday France was arguing that its claim had priority because it had helped in last week's arrest of the ex-spy chief.

Senussi is understood to be in detention in the main police training school in Nouakchott. The facility - surrounded by a high wall blocking the view from outside - was the only one that combined adequate security with a degree of comfort for Senussi, local security sources said.

Senussi is suspected of a key role in the killing of more than 1,200 inmates at Tripoli's Abu Salim prison in 1996. It was the arrest of a lawyer acting for relatives of the victims that sparked Libya's Arab Spring revolt in February last year.

His name has also been linked to the 1988 bombing over Lockerbie, Scotland of a Pan Am jet that killed 270 people. A diplomatic source said on Tuesday the United States was keen to question him about that attack.

(Additional reporting by Marie-Louise Gumuchian and Hadeel al Shalchi in Tripoli, Diadie Ba in Dakar; Writing by Mark John; Editing by Tim Pearce)