Housing finance for owner-occupied commitments in Australia slumped by a seasonally-adjusted 3.9 per cent in June, well above analysts' prediction of a 2 per cent decline.

The total value of housing finance edged down to $20.71 billion, according to the Australian Bureau of Statistics.

A Reuters poll foresees the number of home loans decreasing by a seasonally adjusted 2 per cent, with estimates ranging from a drop of 3 per cent to a climb of 2.4 per cent.

The value of home loans for owner-occupied dwellings edged down 1 per cent to $13.39 billion, and the value of loans for investment housing finance slumped 3.6 per cent to $7.32 billion.

Commitments to purchase new homes plunged 4.5 per cent, while commitments to acquire established homes went down 3.7 per cent, its lowest since October 2000. The number of loan commitments for building homes declined 5 per cent.

The value of owner-occupier housing finance decreased in all states and territories.

The average loan size for first home buyer commitments climbed $3,700 to $285,300.