* Opposition wants partners "without blood on hands"
* Says trying to reassure Baathist government politicians
* Assad government rejects pre-conditions for any talks
* Full meeting of opposition next week to discuss initiative
* WFP says 40,000 have fled fighting in eastern town
Syria's opposition coalition is ready to negotiate President Bashar al-Assad's exit with any member of his government who has not participated in his military crackdown on the uprising, coalition members said on Friday.
Syrian authorities have given no formal response to several offers of talks in recent weeks. But officials say they cannot accept pre-conditions about Assad's departure and have privately dismissed what they say are no more than media initiatives.
The political chasm between the sides, along with a lack of opposition influence over rebel fighters on the ground and an international diplomatic deadlock preventing effective intervention, has allowed fighting to rage on with almost 70,000 people killed in 22 months of conflict, by a U.N. estimate.
Opposition leader Moaz Alkhatib made an offer of negotiations last month without consulting the coalition's 70-member assembly, prompting criticism from a powerful bloc within the movement dominated by the Muslim Brotherhood.
Syrian Foreign Minister Walid al-Moualem is due to visit Moscow, one of Assad's main foreign allies, later this month. Russia also hopes Alkhatib will visit soon in search of a breakthrough to end the bloodiest of the Arab Spring uprisings.
But coalition members say no date has been set for an Alkhatib trip to Moscow and Syria's Foreign Ministry played down suggestions that Moualem and he could meet there, saying any dialogue must take place in Syria.
An overnight meeting of the coalition's 12-member politburo in Cairo endorsed Alkhatib's initiative, although it set guidelines for any peace talks which will be presented for approval by the full assembly next Thursday.
"These guidelines stipulate that Bashar al-Assad and all the security and military leaders that (have) participated in the killing of the Syrian people and whose hands are stained with blood have no place in the Syria of the future," coalition member Abdulbaset Sieda told Reuters in Cairo after the meeting.
"We agreed to reassure the Syrian brothers from the (ruling) Baath Party whose hands are not stained with the blood of the Syrian people that they are partners in the coming political process."
Another opposition member said next week's gathering of the full coalition would try to revive plans for a provisional government, undermined so far by divisions among Assad's foes.
Walid Bunni, one of a handful of liberals in the Islamist-heavy assembly, told Reuters that Assad and his military and intelligence officials could not be part of any negotiations.
"Bashar and his cohorts will not be party to any talks. We will not regard those present from the government's side as his representatives," Bunni said.
He said the meeting addressed how to deal with Iran and Russia, Assad's main supporters, after Alkhatib met the foreign ministers of Russia and Iran in Munich earlier this month.
NO SIGN OF DIALOGUE
Syria's Foreign Ministry complained to the United Nations on Friday over what it said was pressure by Turkey, which backs the rebels, on Syria's opposition to reject any negotiated solution. The ministry said Turkey was "training and arming terrorist groups including al Qaeda" to fight Assad's forces.
Turkey has repeatedly denied arming or training the Syrian insurgents.
Alkhatib has said he is willing to hold talks with Assad's representatives in rebel-held areas of Syria or outside the country to try to end the conflict. Syria's minister for national reconciliation, Ali Haidar, initially gave a positive response, saying he was willing to travel abroad to meet him.
But in an interview on state television this week Haidar reiterated the government's position that any serious dialogue must be on Syrian territory and said the opposition had not formally presented any proposals.
"There is no initiative at the table of the Syrian government," he said. "The government is not a media office to answer ideas through the media."
Haidar has also said the authorities reject any dialogue that aims "to hand power from one side to another".
Alkhatib has headed the Syrian National Coalition since it was founded last December in Qatar with Western and Gulf backing. He has quietly built up a student following and links with civic and religious figures across Syria, although he has no control over armed insurgents seeking Assad's overthrow.
Rebels captured the town of Shaddadeh in the eastern, oil-producing province of Hasakah on Thursday after three days of battles in which activists said 30 members of the al Qaeda-linked, anti-Assad, Nusra Front and 100 soldiers were killed.
The United Nations food agency WFP said on Friday that an estimated 40,000 people had fled Shaddadeh for the provincial capital Hasakah, 45 km (30 miles) to the north.
But the army's firepower in the east remains formidable, rebels say. An activist in the city of Deir al-Zor, where rebels launched an operation this week to expel Assad's forces, came under the heaviest artillery barrages since the start of the conflict from the airport and surrounding bases to the south.
In Damascus, fighting continued on the edge of central areas where rebel brigades have encroached after breaching the Assad forces' defensive lines at the ring road two weeks ago.
Assad's elite Republican Guard and Fourth Division Forces, belonging mostly to his Alawite sect, remain dug in on Qasioun Mountain on the northwestern edge of the capital, at the Mezze military airport on its western edge and in surrounding hills in Somariya and an Alawite enclave known as Mezze 86.
"I hear the shelling from Mezze airport and Somariya and Mezze 86 on Daraya and Moadamiya. From Qasioun it targets Jobar and the southern neighbourhoods," said a local witness.
REBEL TANK BARRAGE
Video footage showed a tank captured by the Liwa al-Islam Brigades, one of the biggest rebel units operating around Damascus, shelling a purported army position in the Eastern Ghouta, an expanse of farmland and urban areas from where opposition forces have been attacking the capital.
Illustrating the dominance of Islamists in the armed opposition, Liwa al-Islam was established by the son of a Salafist sheikh in Saudi Arabia, a major source of funding for the rebels, along with Qatar.
In the northern province of Idlib, where rebels shot down two air force jets on Thursday, Assad's forces shelled the town of Maarat al-Numan after days of heavy clashes around the military base of Wadi Deif on the main north-south highway.
Activist Anas Najm, speaking by phone from the town with the sound of jets buzzing and bombardment in the background, said rebels retook the highway from the army last week.
"The road to Turkey is basically now all under opposition control, except in an area near Aleppo where the regime has a big fortified roadblock," he said.
The Syrian Observatory for Human Rights, which monitors violence in Syria, said dozens of people were kidnapped on Thursday in apparent tit-for-tat sectarian operations in Idlib.
It said pro-Assad armed groups from the Shi'ite Muslim villages of Fua and Kafraya seized four vehicles carrying men and women from the Sunni Muslim villages of Saraqeb, Sarmeen and Binnish. Another group captured 40 people from Fua and Kafraya, it said.
The rebels come mainly from Syria's Sunni majority, while the Alawites follow a faith derived from Shi'ite Islam.