"Antonio Borges, director of the International Monetary Fund's European Department, has notified IMF managing director Christine Lagarde of his intention to leave the Fund for personal reasons," the IMF said in a statement on Wednesday.
Borges, who took up his current IMF post in November 2010, will relinquish his responsibilities immediately.
British-Iranian Reza Moghadam, currently director of the strategy, policy, and review department, has been appointed as Borges successor.
Moghadam is being succeeded by Siddharth Tiwari, who is currently the IMF secretary.
The two would take up their new duties on Thursday.
In a statement, Lagarde said Borges has led the European Department during an extremely difficult period for the region's Eurozone members.
"His vast public and private sector, and academic experience, combined with
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