German retail giant Metro said Wednesday it was in talks with several potential buyers of department store chain Kaufhof, including a real estate group part-owned by a Greek shipping billionaire. \"We are in negotiations with a number of investors,\" a spokesman for Metro told AFP, adding that \"these are exploratory talks, not concrete negotiations about a sale.\" He said they included Austrian real estate group Signa Holding, majority-owned and run by Austrian property magnate Rene Benko, and German investor Nicolas Berggruen, who last year bought Kaufhof\'s rival Karstadt. Signa confirmed to AFP it was in talks with Metro but declined to comment further. According to industry sources, Greece\'s George Economou owns 40-50 percent of the group. The possibility of a takeover by a Greek billionaire of the iconic, 130-year-old chain of department stores comes amid growing German unease about bailing out fellow eurozone member Greece. Metro has been trying for several years to offload Kaufhof, which owns 139 stores, mostly in Germany, and generated sales last year of 3.5 billion euros ($4.8 billion). Spain\'s El Corte Ingles also expressed interest earlier this year. German business daily Handelsblatt on Wednesday quoted a source as saying that Signa\'s approach was \"the first serious attempt to take over Kaufhof,\" adding that a deal could be reached before the end of the year. Handelsblatt put the minimum price for the chain, which employs 20,000 people, at 2.4 billion euros.