Klaus Hubert Georg said an offer for the 120 Karstadt stores from billionaire US-German investor Nicolas Berggruen Holdings and BCBG Max Azria had been accepted.
Two other candidates had put forward offers for the chain, the German-Swedish investment group Triton, and the Highstreet real estate company.
Karstadt was founded in 1881 and owns the famous Berlin department store KaDeWe, but has faced bankruptcy since 2009 after years of erratic management.
Karstadt, which has around 25,000 employees in Germany, became insolvent in the summer of 2009 when its parent company, retail and tourism giant Arcandor, went bust. Arcandor has already sold off its mail order subsidiary Quelle.