Dr Girol Karacaoglu, chief executive of the New Zealand Co-operative Bank, is to leave to become deputy secretary for macroeconomics and research at the New Zealand Treasury. The move will be effective on March 1, bringing an end to his nine years at the bank. Gareth Fleming has been appointed acting chief executive of the Co-operative Bank, from March 1. He was previously a senior executive at ANZ National Bank, and is currently general manager for marketing and products at Co-operative.