"As of today we are only aware of the US nomination," said a World Bank official, speaking on condition of anonymity.

US President George W. Bush announced in late May he had chosen Zoellick, a former US trade chief and deputy secretary of state, to succeed bank president Paul Wolfowitz, who was forced to resign in a favoritism scandal.

Wolfowitz announced his resignation on May 17, under pressure from the development lender's employees association and an internal probe that found he broke rules by arranging a lavish pay-and-promotion package for his companion, a bank employee.

The announcement by Wolfowitz, who leaves office June 30, revived the debate over an unwritten rule that the United States picks the leader of the World Bank and European countries name the head of its sister institution, the International Monetary Fund.

Critics, including nongovernmental organizations and political leaders in developing countries and elsewhere, called for a transparent selection process based on merit, not nationality.

"Future appointments should be made using an open and transparent selection process with candidates not restricted by nationality," South Africa's president Thabo Mbeki said earlier this month.

International development agency Oxfam said the traditional practice "disempowers poor countries, the main clients of the Bank and the IMF."

"The US and other rich countries must now show that they are serious about good governance by allowing the next head of the bank to be appointed based on merit through an open, accountable process," said Bernice Romero, advocacy director of Oxfam International.

The Committee for the Cancellation of the Third World Debt condemned a US-headed World Bank as "simply an instrument at the service of US foreign policy and US multinational interests."