The African Union has extended the mandate of its top official, Jean Ping, after an election for the post ended in deadlock.

Ping, the incumbent chairman of the AU Commission, the bloc's executive arm, did not win enough votes to defeat a challenge by a South African official in four rounds of voting by AU leaders Monday.

Benin's President Boni Yayi, who holds the rotating AU presidency, later said AU leaders have decided to prolong the mandate by Ping and the entire AU Commission until June, when the AU holds its next summit in Malawi.

Monday's voting took place as the AU wrapped up a two-day summit in Ethiopia's capital, Addis Ababa.

Ping, who is from Gabon, has been criticized for the AU's handling of crises in Libya and Ivory Coast, and diplomats said his failure to win re-election was a vote of no confidence in his leadership.

Analysts say the election also exposed divisions between French and English-speaking countries in Africa, and differences between big countries and small ones.

South Africa has indicated that its candidate, veteran anti-apartheid activist Nkosazana Dlamini-Zuma, will run again for the AU Commission chairmanship in June.