AAP

The Australian dollar is sharply lower against its US counterpart, falling as much as half a US cent before regaining a little ground.

Oil prices have fallen per cent after US crude inventories rose for a seventh week, showing that the market is still struggling to ease oversupply despite many producers' efforts to rein in production.

Gold has reached its highest in 3-1/2 months as the dollar fell to a one-week low after the new US Treasury chief poured cold water on the "Trumpflation trade" that had boosted the greenback this year.

Premier Colin Barnett has rejected calls to release the latest costings for the Roe 9 stage of the contentious Perth Freight Link project, saying it would undermine the tender process.

The Australian share market is lower, pulled back for a second successive session by significant falls among the big miners, with weakness among the big four banks further prodding the retreat.

The Australian share market has opened lower, dragged down by major miners on the back of weakness in commodities.

Oil prices have risen but gains have been pared after US government data shows a seventh straight build in crude stocks, suggesting high inventories could undermine OPEC's move to cut output.

The Australian dollar is higher against its US counterpart and has once again jumped above the 77 US cent mark.

Gold prices have lifted 1 per cent to a three-and-a-half-month high after minutes from the latest Federal Reserve policy meeting further dampen expectations for an interest rate rise in March, lowering US bond yields and pressuring the US dollar.

The share market has lost ground on another busy day of company earnings reports, as a fall in commodity prices weighed on the big miners, and Rio Tinto traded without its latest dividend. 

Alcoa's Australian partner, Alumina, has slumped to a full-year loss due to restructuring-related write-offs and lower prices and volumes.

Qantas boss Alan Joyce has defended the airline's financial performance, saying it is outperforming its peers across Asia amid fierce competition on international routes due to lower oil prices.

Australia Post chief executive Ahmed Fahour has made passionate defence of his time in charge of the postal service and says his decision to quit was not sparked by recent criticism of his $5.6 million pay packet.

Mineral sands miner Iluka Resources has slid to a full-year loss of $224 million on the back of hefty write-downs related to a restructuring of the company's business amid the downturn.

Investors taking profits amid corporate earnings season and lower commodity prices are weighing on Australian shares.

The Australian dollar has jumped against its US counterpart and is back above 77 US cents.

Oil prices have fallen 1.5 per cent on expectations of another surge in US inventories, retreating from multi-week highs hit in the previous session after OPEC signalled optimism over its deal with other producers to curb output.

Gold has turned higher as the dollar has shifted lower on Wednesday, after minutes from the last US Federal Reserve meeting showed uncertainty among policymakers about the new Trump administration's economic program.

Well received earnings reports from Woolworths, Coca-Cola Amatil and private hospital operator Healthscope have helped lift the share market.

The WA Liberals are talking up their proposed privatisation of Western Power, announcing details of plans to build a new live export loading berth at Kwinana in Perth's south using funds from the partial sale.

Iron ore miner Fortescue Metals Group has joined larger rival BHP Billiton in forecasting a near-term moderation in iron ore prices, downplaying the rally that has helped it boost profits and lift shareholder payouts.

Woolworths' crucial comparable food sales for the first half have outshone those at fierce rival Coles in a sign that heavy discounting is luring shoppers back.

Woodside Petroleum says it is considering new facilities at Pluto LNG to distribute the fuel in the Pilbara for mining and marine usage, as the company bounced back from large write-downs to post a sharp rebound in profitability for the first half of the 2017 financial year.

Australian shares are flat on the negative side with profit taking in mining and energy stocks and Commonwealth Bank going ex-dividend offsetting some solid corporate results.

Oil prices are up one per cent after touching three-week highs on OPEC's optimism for greater compliance with its deal with other producers, including Russia, to curb output in an effort to clear a glut that has weighed on the market.

The Australian dollar is up against its US counterpart despite the greenback moving broadly higher following hawkish comments from Federal Reserve officials, and finding support amid European political uncertainty.

Gold prices have pared losses on weaker-than-expected US economic data, after falling 1 per cent on renewed expectations of an increase in US interest rates next month that pushed the dollar higher.

The share market has edged lower as a flurry of earnings reports resulted in a mixed performance from many sectors.

BHP Billiton has posted a first-half profit of $US3.2 billion ($A4.2 billion) as a rebound in prices for iron ore and petroleum helped the resources giant swing back to profitability.

Premier Colin Barnett has called on the federal government to pick a figure for the proposed GST floor, saying he would agree to 70 cents in the dollar as the prime minister has indicated.

Kerry Stokes' Seven Group Holdings has slipped to a half-year loss of $41.8 million due to $145 million of write-downs almost entirely related to the value of its stake in Seven West Media.

Engineering firm Monadelphous Group is looking to diversify into new markets such as infrastructure and renewables as revenue from mining and energy customers continues to decline.