We look at how official interest rates and mortgage rates compare in NZ and worldwide - see below.

An economist says floating mortgage rates are out of line with the Official Cash Rate (OCR) and could be further reduced.

His comments come after a Reserve Bank analysis of interest rate margins released on Monday concluded that floating rates seemed to be "unusually" high.

An informal analysis of international rates by nzherald.co.nz shows New Zealand may be no different from much of the world.

CTU economist Bill Rosenberg, however, said another 0.7 per cent to 0.8 per cent could be shaved off floating rates, bringing them down to around 5.7 per cent.

Mr Rosenberg said the Reserve Bank report contained "quite convincing material" on how bank costs had changed.

Interest rates had been under a lot of pressure and floating rates at the main banks had been high for some time, he said. "They are followers rather than leaders."

He said the big four banks were in a competitive situation with Kiwibank, but whether they saw Kiwibank customers as a key part of their market remains to be seen.

He said there was also "room to move" on fixed rates but to a lesser extent.

However, Westpac has said the OCR is less relevant for determining long-term lending rates, and securing offshore funds has become more expensive since the credit crunch hit.

(This information, collected from bank websites, should be used as a guide only.)

New Zealand
Official rate: 2.5%
Average of floating mortgage rates at ASB, BNZ, Kiwibank, Westpac and ANZ: 6.36%

ASB: 6.4%
BNZ: 6.45%
Kiwibank: 5.99%
Westpac: 6.49%
ANZ: 6.45%

Official rate: 3%
Average of floating mortgage rates at NAB, Commonwealth, Westpac, ANZ and HSBC: 5.77%

NAB/Commonwealth: 5.74%
Westpac: 5.81%
ANZ: 5.81%
HSBC: 5.74%

Official rate: 0.5%
Average of floating mortgage rates at Barclays, Lloyds, HSBC, RBS, Cooperative banks: 2.97% to 3.33% (varies according to proportion of loan compared with value of property)

Barclays: 3.24% (60% value) to 3.49% (70% value)
Lloyds: 3.29% to 3.79% (60% value) 3.49% to 3.99% (75% value)
HSBC: 3.59% (75% standard). Special rate 2.74% to 2.95%
RBS: 3.19%
Co-op bank: 2.39%

Official rate: 0% to 0.25%
Common mortgage rates, according to Bankrate.com: 30 year fixed 5.34%,
5 year adjustable: 4.56%