The chief executive of Swiss bank UBS, Oswald Gruebel, has resigned over an alleged 2.3 billion dollar rogue-trading loss. Bank Chairman Kaspar Villiger said in a statement Gruebel feels that it is his duty to assume responsibility for the recent unauthorized trading incident. London-based trader Kweku Adoboli has been charged over the affair. Adoboli was arrested last week and charged with fraud and false accounting. He has been remanded in custody until 20 October. The bank said UBS Europe chief Sergio P Ermotti would take over as interim chief executive.