South Africa, Angola and Nigeria have combined forces to push for an African to head the World Bank for the first time, according to an announcement on Friday, the final day for submitting candidatures, dpa reported. The three countries are backing Nigerian Finance Minister Ngozi Okonjo-Iweala for the post in Washington, which historically has been held by a US-citizen. The other Bretton-Woods institution, the International Monetary Fund, is traditionally headed by a European national. "The endorsement is in line with the belief that the appointment of the leadership of the World Bank and its sister institution, the International Monetary Fund, should be merit-based, open and transparent," the three nations said in a joint statement. "Minister Okonjo-Iweala has all the credentials and qualities to be an outstanding leader of the World Bank Group." Before becoming Nigeria's finance minister, she was the managing director of World Bank for nearly four years. Okonjo-Iweala graduated from Harvard University and obtained a doctorate at the Massachusetts Institute of Technology (MIT) in 1981. Nigeria and Angola are among Africa's top oil producers, while South Africa is the continent's largest economy. World Bank President Robert Zoellick is due to step down this year, and a scramble is already under way to replace him. The US has yet to announce its preferred candidate. When Frenchman Dominique Strauss-Kahn was forced to resign last year from the helm of the IMF, developing nations tried to promote a candidate who was not from the industrialized world. In the end, however, the post went to Christine Lagarde, the former French Finance Minister.