Cairo - Egyptian Investment Minister Mahmoud Mohieldin, a prominent economic liberaliser, will resign from the government to take up a senior post at the World Bank beginning next month, the cabinet said on Wednesday.

Speculation he would join the World Bank has already sparked media discussion about possible successors for his ministerial portfolio, seen as vital to an economic team that has pushed through controversial free market reforms since 2004.

Mohieldin told the Arabic satellite channel al-Arabiya that he was nominated to one of three managing director positions that report directly to World Bank President Robert Zoellick.

The state-run egynews.net website said possible nominees to head the ministry included Ziad Bahaa el-Din, a fellow supporter of liberalisation who works under Mohieldin as chairman of Egypt's financial regulatory authority.

Cabinet spokesman Magdy Rady said Mohieldin would leave the cabinet on taking up the World Bank assignment on October 4. He said the World Bank's board approved the appointment on Tuesday and Egypt replied with its approval the same day.

Mohieldin will oversee World Bank offices involved in finance and private sector development, sustainable development, poverty reduction and economic management, human development and the World Bank Institute, the bank said in a statement.