"Until recently, housing prices have been performing broadly as we expected," ANZ's economist Daniel Gradwell and Jo Masters said.
"In fact, most capital cities are still tracking in line with our forecasts.
"Sydney and Melbourne, however, are not.
"We had expected by this stage to see some evidence that price declines in these cities were moderating, as the impact of credit tightening started to wind down.
"But price falls are continuing at a material pace and are broadening through most segments of these markets."
The revisions for the Sydney and Melbourne outlook are now more in line with fellow economists.
CoreLogic-Moody Analytics however suggest Sydney house prices will grow 0.6 percent in 2019.