METALS, a normally volatile lot, have been even wilder during the past few weeks.

Any hint of where prices are headed - up, down or sideways and for how long - will be of particular interest when BHP Billiton, the world's largest miner, reports its profit results for the latest financial year on Wednesday.

Prices for key commodities, including iron ore, copper and coal have risen between 22 per cent and 52 per cent in the first half of the year, compared with the same period a year earlier. Most mining companies had been predicting that prices will stabilise at current high levels, making for a strong second half.

Despite escalated concerns about the European sovereign-debt problems and potential double-dip recession in the US, the outlook remains relatively unchanged due to two basic fundamentals: supply is constrained and global demand, while moderating, is still growing.

End of sidebar. Return to start of sidebar.

Indeed, slowdowns in the US and European Union are expected to be offset by emerging-market demand, even amid tightening initiatives in monetary policy within huge markets such as China. Weather-related production cutbacks, labour shortages and infrastructure bottlenecks, as well as worker strikes in Africa, have limited output for iron ore, copper and coal, likewise tightening supply and keeping prices firm for the medium and long term.

Spot prices have softened in some cases over the past few weeks, which could provide bargain opportunities for purchasing managers, who aren't dependent on quarterly contracts, and cause others to postpone purchases in anticipation of prices falling further. But the price outlook remains strong for both the medium and long term.

Said Rio Tinto chief executive Tom Albanese during an August 4 conference call when the Anglo-Australian company said its first-half net profit rose 30 per cent: "The combination of strong demand growth and industry supply challenges gives us confidence that real long-term prices and margins for almost all the minerals and metals will continue at elevated levels albeit, of course, with heightened price volatility."

Of more concern are the pace of credit tightening in developing countries, rising costs of existing projects, due to labour and equipment shortages and infrastructure limitations, and uncertainty regarding efforts by governments to tax minerals, or secure ownership stakes in the mines and their profits.

More than 25 countries either announced or implemented changes to tax and royalties, which is giving mining companies pause about new, longer-term commitments. "Resource nationalism is probably, from a strategic standpoint, one of the largest sector challenges we face at the moment, and probably for the next few years," Mr Albanese said.

Several big mining companies have already reported their earnings and, for the most part, reached parity in predictions that the Asian economy has the capacity to offset the crises in the Western world. Mining companies are expecting growth in China's gross domestic product of between 7 per cent and 9.5 per cent. Demand in Japan is expected to be strong due to rebuilding efforts after the earthquake earlier this year.

China accounts for roughly 40 per cent of iron ore and iron pellets for Brazilian mining giant Vale SA. Vale, which posted a 74 per cent rise in second-quarter net income, said its average sales price for iron ore in the second quarter was $US145.30 per tonne, up 58 per cent from the same period one year earlier, and that it expects iron-ore prices to stabilise at today's high levels.

"Even if Chinese demand moderated, growth in Indonesia and India is moving ahead," said Mike Elliott, global leader of Ernst & Young's mining and metals division. "Growth won't be as strong as we thought three or four months ago because of the European and US situations, but we still see prices relatively buoyant."

BHP, one of the last major miners to report profit results in this season, has the benefit of sobering hindsight from the market and commodities meltdown. Analysts expect net profit to reach about $US22 billion ($21.19bn) for the financial year, up 74 per cent from the same period one year earlier, driven largely by higher iron-ore production and a near doubling of iron-ore prices.

Investors will be interested in any hints of softening prices, diminished demand outlooks, or changes in investment plans. The company spent close to $US17bn this year taking over shale-gas producers in the US, and is spending more than $US9bn in Australia this year on expansion projects.

In Australia, where mining accounted for 60 per cent of exports in 2010, companies are placing a series of big bets that industrialising China and India will continue to fuel demand for resources such as iron ore and coal. The government is projecting a 33 per cent increase in capital spending on resources and energy projects in the 12 months to the end of June 2012. Much of the investment is directed to developing new mines or expanding production in sparsely populated Western Australia, especially the dusty Pilbara region that accounts for 40 per cent of the global seaborne trade in iron ore.

This spending is likely to go ahead regardless of global economic disruptions, according to Alan Copeland, manager for resources at the Bureau of Resources and Energy Economics, an Australian government agency. "The process of constructing a project includes contracting or engaging other parties to undertake work or provide equipment. Once these contracts are signed, it can be complex to undo them," he said. However, "to the extent that market conditions may change, companies may re-evaluate the timing and economics of particular projects."