Deutsche Postbank AG is a German retail bank with headquarters in Bonn. Postbank was formed from the demerger of the postal savings division of Deutsche Bundespost in 1990. It became a wholly owned subsidiary of Deutsche Post in 1999, and was partially spun out on the Frankfurt Stock Exchange in 2004. Deutsche Post retained a controlling stake of 50% plus one share until September 2008, when 30% of this was sold to Deutsche Bank for €2.8 billion.