National Australia Bank is transferring an Australian career banker to become chief operating officer of the Bank of New Zealand. BNZ announced yesterday that Paul Suma, the head of private clients for NAB Wealth in New South Wales, will take over as COO in NZ.Suma replaces Stephen Mockett who left last Friday, the BNZ said.Mockett joined the BNZ as head of banking delivery services in June 2009. The BNZ post was Mockett's first job in banking after working in corporate services for Downer EDI in Australia and in management consulting in New Zealand before that.The BNZ made Mockett chief operating officer, looking after strategy as well as operations, later in 2009.The bank also said that its chief risk officer, Martin Philipsen, will leave once a replacement is found.Dianne Maxwell, head of brand at BNZ, is also leaving the bank, to become head of stakeholder management at the Financial Markets Authority.