Australian shares are poised to fall on Thursday as oil prices surged above $100 a barrel amid an escalation in US-Iran attacks on tankers, raising concerns over tighter energy supplies and a prolonged Middle East conflict.

Overnight, the S&P 500, the Nasdaq Composite, and the Dow Jones Industrial Average fell 0.5%, 0.6%, and 0.8%, respectively.

In the macroeconomy, Australia's housing downturn is hitting the top end of the market hardest, with upper-quartile house values in Sydney and Melbourne now more than 10% below their peaks, while lower-priced homes and units remain comparatively resilient, Cotality said in a Thursday report.

In corporate news, West African Resources (ASX:WAF) reported Thursday first-half earnings of AU$0.305 per share on revenue of AU$1.46 billion, compared with earnings of AU$0.162 on revenue of AU$477.3 million a year earlier.

Vulcan Energy Resources (ASX:VUL) reported Thursday first-half loss of 0.11 euros per share on revenue of 2.3 million euros, compared with loss of 0.14 euros on revenue of 4.1 million euros a year earlier.

Australia's benchmark index fell 0.1%, or 9.4 points, to close at 8,911.40 on Wednesday.