The favourable funding market conditions that prevailed in 2012 helped New Zealand banks to build comfortable buffers above the minimum core funding ratio requirements, Sikora said.
Elsewhere in the report, Sikora said that the current year could turn out to be more challenging than 2011-12, with low credit growth expected to limit profit growth in the medium term.
Competition was expected to escalate as banks competed for a smaller pool of available business.
"When combined with anticipated ongoing funding cost pressure, we expect this to have a constraining effect on overall profitability," Sikora said.
On a positive note, he said house prices in New Zealand had abated in an orderly manner in the past few years - more significantly than what had been observed in Australia, where property prices had remained "more inflated".
New Zealand's financial system is dominated by four Australian-owned major banks, which account for about 91 per cent of total assets of all the incorporated banks.