Overall, investment across corporate Australia rose by 5.7 per cent in the June quarter after an upwardly revised 1.0 per cent increase in the previous three months.
Future spending plans also give cause for optimism.
The third estimate for investment in 2008/09 is 26.2 per cent higher than a year ago - the strongest reading in 26 years.
Total investment for the 2008 financial year was $84.8 billion, up 10.8 per cent on a year ago.
The upbeat investment environment suggests national accounts figures - due out on Wednesday - will be better than expected.
CommSec economist Savanth Sebastian said the strength in business spending would help prop up overall economic growth in the quarter and likely add 0.5 per cent to gross domestic product (GDP).
"If you have a look at the numbers overall, they show that the domestic economy remains pretty robust," Sebastian said.
"It's down to the fact that the mining boom is having a significant impact, but it's not just mining. You are seeing it across other areas as well with transportation and construction remaining quite strong.
"The important factor is that there are other economies around the world that are noticing a pretty significant slow down but we're in a much more enviable position.
"It is reassuring for the reserve bank that the death of the Australian economy is not at our doors yet."
The figures will also reassure the Reserve Bank of Australia (RBA) that it has the capacity to deliver an interest rate cut next week.
The central bank will announce its decision on Tuesday and is widely expected to cut the official cash rate by 0.25 percentage points.
Thursday's investment numbers point to an expansion in the productive capacity of the economy and suggest the jobs market will remain on a solid footing, reducing the potential for a wages breakout.
"This sort of gives them some light at the end of the tunnel. We've seen weakness in consumer sentiment, we've seen weaker business sentiment numbers, but really it hasn't translated into a weaker investment number yet," Sebastian said.
"Really, the supply side of the economy is pretty well primed to grow quite rapidly and absorb the inflationary pressures, so wages will remain in check.
"It gives the reserve bank the option of making that rate cut come next week."
A rate cut next week will likely give Prime Minister Kevin Rudd some much needed ammunition to counter what has been a sustained attack from the opposition over his economic credentials.
The opposition continued to blame the Rudd government on Thursday for the dramatic slide in business and consumer confidence since it took office nine months ago.
"I think they've compounded the problem, and I think that's why Wayne Swan really has been the worst treasurer in Australia's history," opposition finance spokesman Peter Dutton said.
"It's just unbelievable that Labor could trash business confidence so quickly and comprehensively.
"There are international factors but it's being compounded in our country by the incompetence of this treasurer."
