* Alkhatib ready for talks in Cairo, Tunis or Istanbul
* Demands release of prisoners, replacement of documents
* Officials have offered national dialogue in Damascus
* Some Assad foes distance selves from Alkhatib comments
BEIRUT, Jan 30 (Reuters) - The head of Syria's main opposition coalition, Mouaz Alkhatib, said on Wednesday he was ready to hold talks with representatives of President Bashar al-Assad outside Syria if authorities released tens of thousands of detainees.
Syrian officials said this week that political opposition figures could return to Damascus for "national dialogue" and that any charges against them would be dropped.
That followed a speech Assad gave three weeks ago in which he called for reconciliation talks, but said there would be no dialogue with opponents he called "terrorists".
Assad has been trying to crush a 22-month-old uprising which began in March 2011 with mainly peaceful political protests but has escalated into a civil war in which 60,000 people have died.
His comments were dismissed by most opposition figures, who insist on his departure as a precondition for talks, but Alkhatib appeared to soften that position slightly.
"I am prepared to sit down directly with representatives of the Syrian regime in Cairo, Tunis or Istanbul," Alkhatib said in a statement on his Facebook page.
He set out two conditions of his own: the release of what he said was 160,000 detainees held in Syrian prisons and intelligence facilities, and instructions to Syrian embassies to issue new passports to Syrians whose documents had expired.
Underlining the continued rifts amongst Assad's foes, the opposition Syrian National Council - some of whose members are represented on Alkhatib's council - immediately distanced itself from his comments.
"The Syrian people are paying a high price to obtain their right to full freedom ... The Syrian National Council affirms its absolute commitment to the Syrian people's will, and rejects any settlement with the Syrian regime or negotiation with it."
Assad announced in early January plans for a reconciliation conference with opposition figures "who have not betrayed Syria", though he said the must first be an end to regional funding and arming of rebels fighting to overthrow him.
"Should we speak to gangs recruited abroad that follow the orders of foreigners? Should we have official dialogue with a puppet made by the West, which has scripted its lines?" he said. (Reporting by Dominic Evans; Editing by Alison Williams)