Reserve Bank governor Graeme Wheeler has rejected criticism by Green Party co-leader Russel Norman that the central bank is biased in favour of Australian banks.
The Reserve Bank took seriously its mandate from Parliament to supervise the New Zealand banking system and did so without favour, Mr Wheeler said in a statement yesterday.
''Australasian-owned banks emerged in better shape from the global financial crisis because of their more conservative management and our economies benefit from that strength."
New Zealand's strong banking system helped see the country through the global financial crisis, he said.
Dr Norman accused Mr Wheeler of misleading Parliament in his first appearance at the finance and expenditure select committee when he told members bank profits were ''about average or below'' most other OECD economies.
Dr Norman claimed data obtained from the Reserve Bank by the Green Party under the Official Information Act showed New Zealand banks' pre-tax returns on assets from 2009-11 made them the fifth most profitable banks in the OECD with only Iceland, the Czech Republic, Singapore and Australian banks more profitable.
Mr Wheeler later released data for the period 2009-11 which showed returns on equity and assets of New Zealand banks appearing to be in line with other advanced economies - excluding euro area countries. The order of countries was the same as given by Dr Norman.
The bank commissioned the data before the committee hearing into the Financial Stability Report on November 7.
However, the analysis was not complete at the time of the hearing at which Mr Wheeler was asked about bank profits.
''My response to the select committee represented my understanding of the information available at that time. Our analysis was completed after the hearing and we released it to the Green Party in response to their request, which followed the hearing. We are now releasing it publicly."
Different measurement practices around the world, including or excluding tax and extraordinary items, meant international comparisons of bank profit figures were not straightforward, he said.
Profits in the New Zealand banking system reflected relatively low levels of non-performing loans, and low cost-to-income ratios compared with many other countries.
Mr Wheeler will tomorrow release the bank's Monetary Policy Statement in which he is expected to clarify issues around what ''for now'' meant in relation to holding the official cash rate unchanged at 2.5%.
