(Adds Qatar on new alliance replacing NATO)
* Gaddafi son seeks to surrender to court
* No confirmation of negotiations from desert
* Qatar: asked to head post-NATO group backing Libya
TRIPOLI, Oct 26 (Reuters) - Saif al-Islam Gaddafi wants to turn himself in to The Hague war crimes court, a senior Libyan official told Reuters on Wednesday.
On the run in the desert, fearing for his life after his father was captured and slain and despairing of any safe haven across an African border, the 39-year-old once expected to inherit dynastic power from Muammar Gaddafi now saw a Dutch prison cell as his best option, the official said.
With him was his relative, former intelligence chief Abdullah al-Senussi, the third man indicted along with the two Gaddafis by the International Criminal Court (ICC) after their crackdown on the popular revolt that began in February.
"They are proposing a way to hand themselves over to The Hague," said Abdel Majid Mlegta, a senior military official for the National Transitional Council. NTC forces toppled Gaddafi in August and overran his hometown and final bastion of Sirte a week ago, capturing the fallen strongman, who was then killed.
An ICC spokesman said it had no confirmation of any talks.
It had hoped to try Muammar Gaddafi himself for crimes against humanity, although Libya's NTC also wanted to have him face justice at home. In the event, the 69-year-old was seized by NTC fighters who filmed themselves beating him before he died, although it remains unclear who killed him.
His rotting corpse was displayed to the public for four days before being buried in a secret desert grave on Tuesday.
Mlegta, citing intelligence sources, said Saif al-Islam, whose British education and talk of liberal reforms once put him at the heart of a rapprochement between his father and the West, was somewhere in the Libyan Sahara far to the south, trying to get an unnamed country to broker a deal with the ICC.
With Senussi, he had contemplated escape into either Algeria, which has taken in his mother, sister and two brothers, or to Niger, where another brother found refuge. However, Mlegta said: "They feel that it is not safe for them to stay where they are or to go anywhere."
Further confirmation of the fugitives' situation was not immediately possible. Mlegta said that, although the Gaddafi family was assumed to have great wealth hidden away, Saif al-Islam lacked the funds to buy safe passage into Niger.
The transformation of Saif al-Islam's image, from that of a relaxed, English-speaking pragmatist into a maker of blood-curdling threats against the "rats" who rose up against his father, saw him join the elder Gaddafi on the ICC wanted list.
His flight and possible capture may not extinguish opposition to the NTC, which on Sunday declared Libya "liberated" after 42 years of Gaddafi's rule and is now working toward forming a government that can hold free elections.
At the pro-Gadaffi tribal stronghold of Bani Walid, where a captive aide to Saif al-Islam told Reuters Gaddafi's son was hiding until last week, tribesmen incensed by retribution from NTC forces warned they were readying an insurgency.
"The Warfalla tribe is boiling inside. They can't wait to do something about this," Abu Abdurakhman, a local resident, said during a tour of his house destroyed by what he said was a revenge attack by anti-Gaddafi forces.
"The Warfalla men of Tripoli and elsewhere are sending around text messages saying: 'We need to gather and do something about this. Let's gather! Let's gather!'"
Libya lacks the sectarian divide and proximity to competing regional powers that turned U.S.-occupied Iraq into a killing ground after the overthrow of Saddam Hussein in 2003.
But it is awash with weapons and with long-standing regional and ethnic rivalries and resentments that could prolong instability as its new leaders and their foreign allies seek to exploit Libya's big oil and gas reserves.
On a pro-Gaddafi website, Zangetna.com, supporters declared: "We promise you, martyred leader, that we will follow your path and we swear to the creator of heaven and earth the blood of martyrs will not be shed in vain." They swore allegiance to "the holy warrior" Saif al-Islam Muammar Gaddafi, calling on him to lead them.
An account of the younger Gaddafi's last days in Bani Walid suggest a degree of panic, however, as his enemies closed in.
"He was nervous. He had a Thuraya (satellite phone) and he called his father many times," said al-Senussi Sharif al-Senussi, an officer who was part of Saif al-Islam's personal security team until Bani Walid fell to the NTC on Oct. 17.
"He repeated to us: don't tell anyone where I am. Don't let them spot me. He was afraid of mortars. He seemed confused."
The NATO alliance whose air power tipped the balance of eight months of fighting in favour of the motley rebel forces says that it sees no immediate military threat and plans to wind up its mission.
But the head of the NTC, Mustafa Abdel Jalil, called at a meeting with military allies in Qatar for NATO assistance to continue until the end of the year.
NATO responded to his remarks by postponing until later this week a meeting that had been expected to formalise a decision to end its Libya mission at the end of the month.
Qatar's top general, Chief of Staff Major-General Hamad bin Ali al-Attiyah, said in remarks carried by Al Jazeera television that Western countries had proposed setting up a new alliance to support Libya after the NATO mission ended.
"And they have asked that it be headed by Qatar because Qatar is a friend of theirs and a close friend of Libya," he added without giving further details.
Abdel Jalil said he wanted NATO help in stopping Gaddafi loyalists escaping justice. But NATO officials at their Brussels headquarters recalled that their U.N. mandate was to protect civilians, not target individuals -- though it was a NATO airstrike on a motorcade in Sirte that led to the elder Gaddafi's capture.
Military experts say NATO's aerial and satellite power would be stretched to detect fleeing convoys in the vast Sahara, which is also out of realistic range for a mission to strike such vehicles, even if NATO's mandate were interpreted to allow it.