The deficit had been predicted last month by the financial institution, after it spent â¬2.3 billion on writing down the value of its holding in Postbank, reports Bloomberg.
Deutsche Bank completed a â¬10.2 billion share sale this month to aid the purchase the rest of Postbank, with the firm looking to reduce its reliance on investment banking operations, as well as boosting its capital levels.
Peter Braendle, a spokesman for Swisscanto Asset Management in Zurich, said: "It makes sense to build up the stable businesses to reduce dependence on investment banking."
Deutsche Bank's investment arm recorded a four per cent drop in sales and trading during the third quarter.
Josef Ackermann, chairman of the management board of the bank, defended the group's results as showing the "robustness" of the organization's updated business model in the face of difficult market conditions.
By Claire Archer