Karstadt Warenhaus GmbH is a German department store chain whose headquarters are in Essen.Up until 30 September 2010 the company was a subsidiary of Arcandor AG (which was known until 30 June 2007 as KarstadtQuelle AG) and was responsible within the group for the business segment of over-the-counter retail.On 9 June 2009 Essen District Court ordered provisional asset administration and protective measures in response to an application for the opening of insolvency proceedings.