ANZ Bank has warned the pace of decline in Australia's house prices is "quite a bit larger" than expected, and likely to last longer than it previously forecast.

With national auction clearance rates at a five-year low, ANZ senior economist Daniel Gradwell predicted in a research note published on Wednesday that further weakness was in store for the housing market, before it would start stabilising later this year.

There is more weakness in store for the housing market, research from ANZ Bank said. Credit:James Alcock

Mr Gradwell pointed to recent figures showing that the rate of price decline had accelerated in Sydney. The weakness was also affecting Melbourne amid a slump in national auction clearance rates and a tightening in credit availability.

Mr Gradwell said the bank had previously expected the market would have "stabilised" by now, based on higher auction clearance rates at the start of this year. It had expected prices would finish 2018 slightly higher in annual terms.