The Australian bourse was more than 1.5 per cent higher on Wednesday noon as better than expected local economic growth figures boosted investor sentiment.

At midday (AEST), the benchmark S&P/ASX200 index gained 73.7 points or 1.67 per cent at 4,477.9 points. The broader All Ordinaries index, meanwhile, edged up to 4,508.4 points after adding 69.6 points or 1.57 per cent.

All sectors posted improvements, with materials up by 2 per cent and financials increasing 1.9 per cent.

On the Sydney Futures Exchange, the September share price index futures contract added 81 points at 4,468 on volume of 20,571 contracts.

Only one company in the S&P/ASX50 was in the red.

Domestic investors were propped up by stronger than expected economic growth data, according to CMC market analyst David Taylor.

National gross domestic product (GDP) increased 1.2 per cent in the three months to June for an annual rate of 3.3 per cent, the Australian Bureau of Statistics said.

Economists predicted a quarterly rise of about 0.9 per cent for an annual rate of 2.7 per cent.

"We got better than expected GDP data just a few moments (ago)," said Mr Taylor.

"The anticipation of that and the fruition of that has probably pushed us well into positive territory... led by the banks, the miners and the energy companies."

Resource giant BHP Billiton edged up 70c or 1.89 per cent at $37.75. Rio Tinto strengthened by $1.91 or 2.73 per cent at $72.00.

"We are very leveraged towards China, and Chinese growth is still moving along quite nicely," he said.

"In our GDP figures, that exposure to China gives us a quite significant advantage over the world.

"The lift we have got today is investors have refocused on our economy and our miners."

National Australia Bank added 60c or 2.59 per cent at $23.80. ANZ increased 51c at $23.10, while Westpac had ascended to $22.20 after gaining 50c. Commonwealth Bank was 68c higher at $50.98.