The old alliance of Europe and America faces a huge row with the rest of the world over the identity of the next head of the World Bank, after president Robert Zoellick said on Wednesday he is to leave his post in June.

World Bank president Zoellick is to leave in
June 2012 - but should the next leader be an
American too?
Photograph: Christophe Karaba/EPA

While his departure had been widely expected, the news kicks off the process of finding a new leader, who has traditionally been an American under an informal agreement dating to the founding of the bank 68 years ago. Speculation has focused on either U.S. Secretary of State Hillary Clinton - who is also rumored to have an eye on a run for the White House - or former Treasury secretary Larry Summers as Zoellick's likely successor. When Dominique Strauss-Kahn was succeeded by his countrywoman Christine Lagarde at the International Monetary Fund last year, it was widely rumored that America had agreed to let Europe keep its traditional grip on the IMF – in the face of calls for a candidate from an emerging country – as long as France and other European governments backed Clinton as the new boss of the World Bank when the job came up.

However, calls to widen the search to include candidates from outside the U.S. began immediately. Campaigners including Oxfam, Eurodad and the African Forum and Network on Debt and Development (Afrodad), issued a joint statement appealing to America not to continue its monopoly of the role.

Elizabeth Stuart of Oxfam said: "The way the World Bank picks its president needs to change. The bank only operates in developing countries, so any candidate not supported by a majority of these countries would plainly lack legitimacy."

In an open letter to governors of the World Bank, which provides loans to developing countries for capital programs, the campaigners demanded that: the new president is selected by a majority of World Bank member countries; that the selection process is open to anyone to apply; and that a clear job description and required qualifications is set out, including "a strong understanding and experience of the particular problems facing developing countries".