The $173.5 billion in estimated capital spending represents 94 projects at an advanced stage of development and includes 35 mineral mining projects, 35 energy projects, 20 infrastructure projects and four processing projects.

ABARES acting deputy executive director Terry Sheales said the increase in planned capital spending reflected the mining sector’s confidence in the medium and long-term outlook for the country’s mineral and energy commodities.

“Commodities attracting the most investment are oil and gas, iron ore and coal and associated infrastructure which collectively account for around 92 per cent of all committed capital expenditure,” he said.

“These are the sectors in which significant export growth is likely to occur.”

Major additions to the advanced list include a number of large iron ore and coal projects, including investments by BHP Billiton, Fortescue Metals and Rio Tinto in several coal and iron ore developments over the next three years.

The mining heartland of Western Australia accounted for 63% of the advanced capital spending, while Queensland accounted for 28% of the spending.

ABARES estimates new capital expenditure in the mining industry to be $55.5 billion in 2010-11, 53% higher than in 2009-10, while 10 projects with a combined capital cost of $2.8 billion were completed in Australia in the six months to April.

In the meantime, ABARES expects spending on exploration in Australia’s minerals and energy sector to be $5.9 billion in 2010-11, broadly similar to expenditure in 2009-10.

“Investment in mineral exploration remains strong, with Australia expected to record its third highest annual mineral exploration expenditure in 2010-11,” ABARES said.

ABARES said spending on brownfield exploration accounted for around 60% of Australia’s total mineral exploration expenditure over the past eight years.

“Two factors have contributed to this trend,” ABARES said. “First, higher world prices have encouraged companies to reassess reserves previously considered uneconomic. Second, brownfield mining is attractive for companies because infrastructure often already exists, which means extraction can start sooner and capital costs are lower.”