In Australia, a government-backed review of whether the major banks can survive a global financial crisis is calling for them to hold stronger capital levels.
Analysts say the Australian banks - which are the parent companies of New Zealand's main retail banks - need $A48 billion to move to the top quartile of global banks.
The Financial System Inquiry said their capital levels need to rise to 12.2 percent of total lending to be in the top quartile of international banks, from current levels of between 10 and 11.6 percent.
Industry analysts said that would mean each bank having to raise $A10 to $A12 billion in extra shareholder funds.
That would lower their profitability, and potential returns to shareholders, but also make them far less likely to collapse in a major recession.