Radovan Jelašić, the governor of the National Bank of Serbia, on Tuesday resigned with more than two years to run his second term.
Jelašić, governor since 2004, said the resignation was irrevocable and due to personal reasons. His current term was due to end in September 2012.
He is expected to remain in office until his successor is named.
The governor is well regarded by investors and the dinar fell on the surprise news of his departure.