* CFO Manfred Wimmer to retire in September
* Risk Chief Mittendorfer to become CFO
* Former Deutsche Bank exec Gottschling to become CRO (Adds Erste comments and background)
VIENNA, June 20 (Reuters) - Erste Group Bank Chief Financial Officer Manfred Wimmer will retire in September and be replaced by Chief Risk Officer Gernot Mittendorfer, the Austrian lender said on Thursday.
"Manfred Wimmer will be leaving the management board at his own request and retire as of Sept. 1, 2013," the third-biggest lender in central and eastern Europe said in a statement.
Wimmer, 57, has been CFO since September 2008, playing a low-key public role next to flamboyant Chief Executive Andreas Treichl. His contract was to run until June 2017.
Mittendorfer, born in 1964, joined the management board in January 2011 after a career at the group starting in 1990.
An Erste spokesman said there was no more to the change than Wimmer's desire to step down after contributing 35 years to the pension system.
"For people from the United States or UK it is unusual but that is the normal retirement age in Austria," he said, adding the step did not reflect any differences over strategy.
Erste is the second big Austrian bank to revamp top management this month after Raiffeisen Bank International named veteran insider Karl Sevelda to succeed Herbert Stepic as chief executive.
Stepic, 66, had denied wrongdoing in using front companies in the Caribbean and Asia to buy three apartments in Singapore, and said he decided to quit last month to spare the bank a damaging debate about his personal investments.
The Erste spokesman said Wimmer had no similar issues and owned flats in Vienna and the Austrian province of Carinthia.
Andreas Gottschling, until recently head of risk analytics and operational risk management at Deutsche Bank, would become CRO in September, the bank said. The German national is an adviser at McKinsey management consultants.
Wolfgang Schopf, Erste's head of performance management, will become CFO at Erste's Czech unit Ceska Sporitelna as of Aug. 1. (Reporting by Michael Shields; editing by Georgina Prodhan)