Audi chairman says will take 'bit of time' to replace Piech on board
Piech and his wife quit their board seats at the VW group on April 25 after a public showdown with Winterkorn.
Separately, sales chief Luca de Meo said Russia would remain a growth market for Audi over the long term despite the ongoing auto slump amid the country's economic crisis.
(Reporting by Andreas Cremer; Editing by Maria Sheahan)