"Mr. Zoellick brings to the bank presidency strong leadership and managerial qualities as well as a proven track record in international affairs and the drive required to enhance the credibility and effectiveness of the bank," the World Bank board said in a statement.

Grilling

Zoellick was interviewed on Wednesday by the board for four hours on issues related to strategic directions, leadership, corporate governance, the multilateral environment and independence of the bank.

As well as focusing on Africa Zoellick wants to define a clearer role for the World Bank in emerging nations like China, India and Brazil, which are still dogged by high poverty levels despite their rapid economic development.

Zoellick faces daunting challenges in taking up the new post.

"There is no doubt that the institution has been through a  period of turmoil and I think that one of the tasks of a new  president will be to try to calm the waters," Zoellick said in  Berlin this month on a global "listening" trip.

Low morale

The president of the World Bank serves a renewable, five-year  term.

Under an unwritten agreement, the US chooses the head of the World Bank and European countries select the leader of its sister institution, the International Monetary Fund.

The lengthy scandal that led to the resignation of Wolfowitz, who was found last month to have violated rules in arranging a generous  pay-and-promotion package for his girlfriend, had divided the staff  and cast a cloud over the credibility of the development lender.

Zoellick’s five-year tenure begins in the middle of the bank's critical year-long fund-raising for its lending programs to its poorest borrowers, which will set the course of the bank for the next three years starting in the middle of 2008.