Syrian opposition groups meeting in the Qatari capital signed a primary agreement to form a united group called the Syrian National Coalition.
Details of the agreement are still being negotiated; a delegate at the talks told reporters they would discuss specifics at meetings on Sunday night.
Cleric Moaz al-Khatib, former Sunni Muslim imam of the Umayyad mosque in Damascus, who is seen as a moderate will head the government in waiting.
“An initial deal has been signed. The evening session will be for electing the president of the body and his deputy,” Ali Sadreddine al-Bayanouni, a Muslim Brotherhood delegate at the talks, told reporters.
The Syrian National Council – once seen as the leading representative of the opposition but now seen in the West as dominated by out-of-touch exiles – had come under increasing pressure to accept a unity plan.
They are trying to work out the final details of the agreement, which is how many seats are to be given to the main opposition parties, our correspondent said.
“We have started an open dialogue with our brothers and looked at their initiative,” the SNC’s new leader George Sabra said earlier in Doha before the coalition formation announcement.
“But we have our own point of view and our own ideas that we plan to put forward.”
Sabra said “the SNC is older than … any other initiative” on the table, adding that no opposition group should be forced under the banner of another.
“The meeting is still on, but there has been real progress. There will be a political agreement for common action, a political body to supervise military action,” he said.
The SNC had already twice asked for a postponement of the talks on plans for a broad-based government-in-waiting.
Its counter-proposal envisages the formation of a provisional government pending a general congress of the opposition, according to a document seen by AFP news agency.
The existing plan, inspired by Riad Seif who is reportedly seen by the US administration as a potential new opposition chief, envisages the formation of a transitional government, a military council to oversee rebel groups and a judiciary to operate in rebel-held areas.
Syria’s information minister, Omran al-Zohbi, called for a national dialogue, and said the army was fighting to boost the chance for talks.
“The only way to succeed in Syria is to sit down at the table to launch a national dialogue,” he said.
“The opposition must accept the choice of dialogue and … the army, by facing down terrorism, is protecting this dialogue.”
On the ground inside Syria, there was no let-up in violence on Saturday.
The Syrian conflict that has been raging for the last 20 months started during the Arab uprising that rocked the Middle East forcing long serving leaders to quit the reins of power.