* Alkhatib's authority had been undermined
* Resignation hits moderate wing of uprising
The head of Syria's main opposition group resigned on Sunday, in a blow to a diminishing moderate wing of the two-year uprising against President Bashar al-Assad's rule.
Moaz Alkhatib, a former imam of the Umayyad Mosque in Damascus who had offered Assad a negotiated exit, was picked to head the Western and Gulf-backed National Coalition for Syrian Revolutionary and Opposition Forces in November after leaving Syria following persecution and several stays in jail.
Al-Khatib's resignation came after the coalition berated him for offering Assad a deal and after the group went ahead, despite his objections, with steps to form a provisional government that would have further diminished his authority.
"I had promised the great Syrian people and promised God that I would resign if matters reached some red lines," Alkhatib said in a statement on his official Facebook page, without explaining exactly what had prompted his resignation.
"Now I am fulfilling my promise and announcing my resignation from the National Coalition in order to be able to work with freedom that cannot be available within the official institutions," he said.
A spokesman for Alkhatib confirmed his resignation.
Last week, the coalition chose Islamist leaning technocrat Ghassan Hitto as a provisional prime minister to form a government to fill a power vacuum in Syria arising from the two-year-old revolt that has killed more than 70,000 people.
Alkhatib, who had argued insufficient groundwork had been done to start forming a government, was weakened considerably, along with a moderate wing of the revolution as Jihadist salafists play a bigger role on the battlefield.
Hitto, whose cabinet is supposed to govern rebel-held areas currently ruled by hundreds of brigades and emerging warlords, was backed by the Muslim Brotherhood and coalition Secretary General Mustafa Sabbagh, who has strong links with Qatar.
"Basically Qatar and the Brotherhood forced Alkhatib out. In Alkhatib they had a figure who was gaining popularity inside Syria but he acted too independently for their taste," said Fawaz Tello, an independent opposition campaigner.
"They brought in Hitto. The position of Alkhatib as leader became untenable."
The appointment of Hitto prompted nine people to suspend their membership in the 62 member body, saying that promises to reform the coalition and respect consensus have been discarded.
Earlier this year, Alkhatib floated an initiative for the opposition to talk to Assad's administration about a political transition, but said the Damascus government did not respond.
In his statement, Alkhatib added: "We will follow the path with our brothers who aim for the freedom of our people."
He said official positions were "means to serve noble objectives" and not an aim in themselves.
Moaz al-Shami, a leading activist in Damascus, said Alkhatib's resignation deprived the coalition, which consists mostly of exiles, of the figure best known inside Syria, but that Alkhatib still could still play a major role in the revolt.
"The opposition does not deserve Sheikh Moaz. He is a moderate and a non-sectarian figure who was acting like the statesman Syria should have. A lot of people did not agree with his peace offer to Assad but they respected him," Shami said.
Syrian opposition leaders are due to attend an Arab League summit this week, Qatar said earlier on Sunday, looking for more support for their armed uprising.