The head of a controversial Arab League observer mission to Syria has resigned, an Arab League official told AFP on Sunday.

The resignation of General Mohammed Ahmed Mustafa al-Dabi was due to be officially announced at a meeting of Arab foreign ministers in Cairo later in the day, the official said, without saying why the Sudanese former military intelligence officer had quit.

Arab countries were meeting in Cairo in a renewed push to end Syria's bloody 11-month crackdown on dissent, as fighting escalated, even spilling into neighbouring Lebanon.

The resignation comes as the ministers discuss the possibility of sending a joint UN-Arab mission to Syria, the official said.

He added that Arab League Secretary General Nabil al-Arabi also met with Jordanian former foreign minister Abdel Ilah Khatib, who has been proposed as the next Arab envoy to Syria, the official said.

Gulf Arab states that have spearheaded regional condemnation of President Bashar al-Assad's regime held talks in the Egyptian capital before a meeting of an Arab League committee on the crisis.