In an extraordinary turn of events, the German city of Hanover is preparing to file a law suit to stop the Belgian beer giant Interbrew from buying Gilde Brauerei. Interbrew announced a €525m deal on Friday to acquire Brauergilde Hannover, the parent company of the German brewer. Interbrew also offered to buy the 14.6% of Gilde that Brauergilde Hannover did not own, once the first deal had been completed.