European Central Bank chief economist Juergen Stark has resigned amid speculation of conflicts within the ECB over its bond-buying programme.
The ECB said he was leaving ''for personal reasons'', but would stay in the job until a successor is found.
Analysts said Mr Stark's surprise move pointed to continuing divisions in Germany over the ECB's direction.
The BBC reports European stock markets fell after the news, on concerns that any differences within the ECB would make tackling the eurozone debt crisis more problematic.
Mr Stark's departure comes almost three years before his term is due to expire in May 2014.
He was reportedly one of four members of the ECB who voted against a decision last month to revive a programme of buying the bonds of indebted eurozone nations.
In February, former Bundesbank President Axel Weber quit the ECB over the bank's policy of buying the debts of troubled eurozone governments.
The BBC reports the ECB has bought more than 35 billion euros in bonds in recent weeks, on top of the 76 billion euros in Greek, Irish and Portuguese bonds it has bought since May 2010.
There were reports on Friday that German deputy finance minister Joerg Asmussen will be appointed to replace Mr Stark.
