Swiss National Bank (SNB) Chairman Philipp Hildebrand (L) and SNB President Hansueli Raggenbass attend a news conference in Zurich, January 5, 2012. Switzerland's central bank chief said on Thursday he saw no reason to resign over a controversial currency transaction done by his wife, which prompted speculation she had benefited from privileged information. Hildebrand's decision to speak came after the sacking on Tuesday of a bank employee who leaked details of the trade to the lawyer of a political adversary. REUTERS/Christian Hartmann (SWITZERLAND - Tags: BUSINESS)