Brigadier General Manaf Tlas, one of the most senior defectors from President Bashar Assad's rule, said he would help unite Syria's fragmented opposition inside and outside the country to agree on a roadmap for a transfer of power, Haaretz reports.
Tlas, speaking in a newspaper interview in the Saudi city of Jeddah, also said he was looking for support from Saudi Arabia and other powers.
"I am discussing with...people outside Syria to reach a consensus with those inside," Tlas told the Saudi newspaper Asharq al-Awsat. "I left [Syria]...to try to help the best I can to unite the honorable people inside and outside Syria to set out a road map to get Syria out of this crisis".
Tlas, a former friend of Assad's who could play a role in any transition of power, said he "did not leave Syria to lead the transitional period".
"A group (including opposition) from inside and outside Syria should cooperate to accomplish this phase."
The general, a Sunni Muslim member of Assad's mostly Alawite inner circle and a senior officer in the Republican Guards, defected earlier this month.
Meanwhile, Damascus and Syria's second biggest city, Aleppo, came under shell fire from government forces battling the growing insurgency, opposition activists in the area said.
Residents in southern Damascus reported a shell landing in southern areas of the capital every minute.
After a major assault on rebels in Damascus last week, the army has turned to Aleppo, reinforcing troops there with an armored column that had been operating in a northern province.