Leaders of the 53-nation African Union are beginning three days of talks in the Ethiopian capital Addis Ababa on Sunday. But the discussions are likely to be overshadowed by differences over which country should chair the organisation. Libya has chaired the AU for the past year. Under the system of rotating regional blocs, the job should go to a southern African leader. Consensus has emerged around the Malawian President Bingu wa Mutharika, but the Libyan President Moamar Gaddafi wants to stay on.