World Bank President, Jim Yong Kim has made the surprise announcement that he is stepping down after six years in the post.
His resignation will take effect from 1 February.
Mr Kim, 59, was not due to leave until 2022, after he was re-elected for a second five-year term in 2017.
He will "join a firm and focus on increasing infrastructure investments in developing countries", the World Bank said.
In a statement, Mr Kim said: "It has been a great honour to serve as President of this remarkable institution, full of passionate individuals dedicated to the mission of ending extreme poverty in our lifetime".
No reason was given for his unexpected resignation.
Kristalina Georgieva, the World Bank's chief executive officer, will assume the role of interim president.