Bank Metzler, the 300-year-old German private bank, has been appointed by the German federal government to find a buyer for the Bundesdrückerei, the banknote printing group, just two years after advising on its privatisation.

The original privatisation went sour last month. It had been won by Apax, the private equity firm, for e1bn ($971m), with e500m of debt from Helaba and a e230m vendor loan payable in 2010. Apax rechristened the group Authentos and acquired Security Printing and Systems, the UK passport printer, but e400m of losses from the group's smartcard subsidiary left it on the brink of insolvency.