AAP

Fly-in, fly-out workers are increasingly afraid to report mental health issues because they don't want to be made redundant by struggling mining companies, a Western Australian parliamentary inquiry has heard.

Listed companies that hoard large amounts of cash have underperformed since the GFC and should start spending, accounting firm Deloitte says.

Shares in Kerry Stokes' Seven Group Holdings have soared on the firm's plans for a share buy-back and despite a 74 per cent drop in first-half profit to $68.4 million.

The market has opened flat despite fresh records on Wall Street on the back of positive congressional testimony by US Federal Reserve chair Janet Yellen about interest rates.

Troubled mining services contractor Macmahon Holdings has fallen into the red with a first-half loss of $112.45 million.

The Dow and S&P 500 have bolted to fresh records after Federal Reserve chair Janet Yellen pledged a cautious approach to raising interest rates.

Oil prices have slipped as traders estimated a key report will show another increase in US crude inventories that already are at record levels, exacerbating the global oversupply.

The Australian dollar is higher after US Federal Reserve chair Janet Yellen said an interest rate before June is unlikely.

Gold prices fell to the lowest level in almost two months on Tuesday after Federal Reserve chair Janet Yellen waxed positive about the economy's performance, even as she appeared to temper any expectations of an imminent rate increase.

BHP Billiton has scrapped the sale of its US Fayetteville shale assets in the face of weak oil prices, less than four months after it was announced, and announced big cuts to its capital spending.

The Australian share market has closed slightly higher, boosted by what investors considered a good financial result from BHP Billiton despite a big drop in the global miner's profit.

QBE Insurance Group is confident it has finally turned the corner after lifting its full year profit by more than $1 billion.

Western Australian taxi patrons who pay their fare with non-cash methods will no longer be slugged a surcharge of up to 11 per cent.

The Australian sharemarket is lower following a lacklustre performance on Wall Street ahead of congressional testimony by Federal Reserve chair Janet Yellen.

US stocks have finished little changed following lacklustre housing data on the eve of congressional testimony by Federal Reserve chair Janet Yellen.

Mining giant BHP Billiton's half-year net profit has dived by 47.4 per cent to $US4.3 billion ($A5.52 billion) after a period of plummeting iron ore prices.

The Australian dollar is back below 78 US cents as commodity prices fall and the US dollar bounces back from last week's fall.

Oil prices have fallen, extending last week's slide as US crude supplies linger at historic levels.

Gold prices have fallen, as a deal between Greece and its European creditors calms nerves in asset markets and lessens the need for holding gold as a hedge against uncertainty.

Troubled mining services company Boart Longyear is confident demand for its services will pick up eventually, despite posting a $US333million first-half loss during the 2014 calendar year.

Strength in the financial and property sectors has lifted the share market.

The housing boom will continue to drive earnings in the medium term, says global construction group Lend Lease, which lifted half-year profit by 25 per cent to $315.6 million on the back of strong demand for apartments.

The Australian share market has opened flat as investors exercise caution until they get a clearer picture of how Greece's debt situation will unfold.

Engineering group UGL has suffered a first-half loss due to one-off write-downs and provisions as the slowdown in resource sector investment continues to bite.

The Australian dollar is higher, as market sentiment improves on the back of a positive outcome in the Greek bailout negotiations.

Gold prices have fallen as a deal between Greece and its creditors took shape, easing worries about the eurozone and driving investors out of the haven metal.

Perth Mint says a new agreement allowing the Australian Crime Commission access to documents is not related to any investigation.

The Australian share market has closed lower in a choppy session bereft of positive drivers.

Gas and power transporter DUET Group has stuck with its guidance for full year payouts to its shareholders despite a 60 per cent fall in half year profit.

Adelaide-based oil and gas producer Santos has frozen its senior executives' salaries after falling to a $935 million full year net loss.

The Australian share market has opened almost flat after a mixed night of trade on overseas stock markets.

A disappointing forecast from Wal-Mart and weakness in oil stocks have pushed the Dow lower, while the Nasdaq edged closer to 5,000 thanks to strong results from Priceline.