ALMOST half the properties listed for auction in Sydney at the weekend failed to sell, reflecting the fragile confidence of the market.

Andrew Wilson, a senior economist for the Fairfax Media-owned Australian Property Monitors, said the reported results represented a clearance rate of 53.1 per cent.

The uncertainty would have been influenced by Tuesday's decision by the Reserve Bank to leave official interest rates on hold, he said, despite widespread expectations of a cut. This was followed by a decision by ANZ and Westpac to raise their mortgage interest rates.

''Fragile confidence and low housing affordability in the Sydney housing market remains a significant barrier to increased housing market activity in a city that remains clearly Australia's most expensive capital for housing,'' Dr Wilson said.

The most expensive property sold at auction was a three-bedroom townhouse in Kirribilli for $1.71 million, while the most affordable was a three-bedroom house in Terrigal that went for $109,500.