African Union leaders are meeting for their first summit since the death of Muammar Gaddafi, the bloc's founder, with the selection of top officials and discussion of crises on the continent dominating the agenda.

The leaders, gathered in Ethiopia's capital, Addis Ababa, on Sunday for a two-day summit have chosen Thomas Boni Yayi, Benin's president, as the 54-member bloc's new chairman.

"The development of our continent is in our hands my dear presidents...it is in unity and cohesion that our continent will ensure its development"

- Thomas Boni Yayi, president of Benin

Yayi, who succeeded Equatorial Guinea's President Teodoro Obiang Nguema AU chairman, said he wanted to "ensure that peace comes back our continent," as he accepted the post with "humility" for "the high responsibility."

"We shall continue to work hand in glove to ensure that we consolidate all what we have achieved so far," Yayi said.

War-torn Somalia, oil disputes between Sudan and South Sudan, violence in Nigeria and riots in Senegal in response to the president's determination to cling onto power, are also expected to be addressed in sideline talks.

The AU chairmanship rotates among African leaders and is held for one year, but intense lobbying continues ahead of a vote for the top job, the head of the bloc's executive arm, the AU Commission.

Tight race

South Africa's Home Affairs Minister Nkosazana Dlamini-Zuma's move to challenge the incumbent Jean Ping has made the race for the post tighter.

South Africa said on Saturday it was optimistic Dlamini-Zuma, former wife of President Jacob Zuma, can unseat Gabon's Ping, who was first elected in 2008.

"Government remains optimistic that Minister Dlamini Zuma will receive the necessary votes," South Africa's foreign ministry said in a statement, hoping she will be the first woman to hold the post.

The election by secret ballot will be held on Monday.

The AFP news agency reported sources close to Ping as saying he is confident of re-election, counting on support from French-speaking West and Central Africa countries.

However, Dlamini-Zuma, 62, has launched a tough campaign and has the backing of the 15-member Southern African Development Community.

Pretoria has been lobbying hard across the continent to drum up the two thirds of the vote needed.

The two-day summit, being held at a sleek new Chinese-built AU headquarters inaugurated on Saturday, will also focus on boosting "Intra-African Trade," the meeting's official theme.

The African leaders will also discuss the long-running conflict in Somalia, where the AU has a 10,000-strong force protecting the country's fragile Western-backed government from the al-Qaeda-linked al-Shabab group.

A bitter dispute between Sudan and South Sudan over oil pipeline transit fees, heightening tensions between the former civil war enemies, is also hoped to be addressed during the two-day talks.

Meanwhile, Ban Ki-moon, the UN secretary-general, told African leaders gathered in Addis Ababa, that discrimination based on sexual orientation "had been ignored or even sanctioned by many states for far too long".

He said African nations should stop treating gays as "second-class citizens, or even criminals".

Ban said it would be challenging for Africa to "confront this discrimination".

There was no immediate response from African heads of states to Ban's speech. Many African countries outlaw homosexuality and many African churches preach against it.

PHOTO CAPTION

African leaders pose for a group photograph with U.N. Secretary-General Ban Ki-moon during the 18th African Union (AU) summit in Ethiopia's capital Addis Ababa January 29, 2012.

Aljazeera