New Zealand banks are moving quickly to lower mortgage lending rates after the Reserve Bank of New Zealand cut its official interest  rates.

Kiwibank, ASB and ANZ have dropped mortgage rates after the Reserve Bank of New Zealand cut the Official Cash Rate (OCR) to 3.25 per cent from 3.5 per cent on Thursday.

Kiwibank has reduced its variable and revolving rates from 6.65 per cent per annum to 6.40 per cent immediately for new customers and in two weeks for existing.

ASB dropped its variable home loan and Orbit home loan rates by 0.25 basis points to 6.5 per cent effective from Friday for new customers and June 19 for existing customers. Other lending and deposit rates are currently under review, ASB says.

ANZ said it was lowering its floating and flexible home loan rates by 0.25 per cent in line with Thursday's cut.

"I would have expect the banks to move quickly on floating rate mortgages," Reserve Bank governor Graeme Wheeler said at a press conference after the announcement.

"You'll probably see some decline in fixed mortgage rates, maybe two and three year mortgage rates for example," he said.