The surprise announcement of his candidacy came after Egypt withdrew Diplomat Mustafa Al-Fikki from the race just moments before voting for the Head of the 22-member body was due to start.
A Diplomat under the regime of Egypt’s ousted President Hosni Mubarak, Al-Fikki had faced strong opposition both on the Egyptian street and from within the League, sources said.
Al-Arabi’s nomination had been quickly followed by the news that Qatar withdrew its candidate - and the only other contender - Abdulrahman al-Attiyah, a former Gulf Co-operation Council Secretary General, from the race.
A US-educated international law expert, Al-Arabi was one of 15 judges at the UN International Court of Justice from 2001 to 2006, sitting on several international arbitration panels.
Arab Foreign Ministers had gathered in Cairo earlier yesterday to begin discussions on who would succeed Amr Moussa as the Secretary General of the pan-Arab Organization.
Moussa has decided to contest the top job in his native Egypt, in the first Presidential election since Mubarak was overthrown in February following 18 days of popular protests.