* Australia Q2 GDP +3.4 pct y/y, vs 2.8 pct consensus
* Weak commodity prices hurt materials (tmsnrt.rs/2jvdmXl)
* Orocobre slumps on Argentina export tax impact
(Updates to close)
By Nikhil Nainan
Sept 5 (Reuters) - Australian shares extended their losses to a fifth straight session on Wednesday, closing 1 percent lower and brushing aside a robust economic growth report as materials stocks slid on weaker commodity prices.
The S&P/ASX 200 index .AXJO dropped 62.7 points to close at 6,230.4, its sharpest one-day fall in two weeks.
U.S.-China trade tensions continued to weigh on commodity prices with Shanghai copper hitting its lowest in more than a year overnight, tracking a 2.6 percent drop in London-traded copper. MET/L
Australian materials stocks took note, with the sector index .AXMM ending 2.4 percent lower.
Orocobre Ltd ORE.AX was the biggest loser, sliding 13 percent as the company evaluated the possible impact of Argentina's temporary foreign trade measures on its Argentine interests. global miners BHP BHP.AX and Rio Tinto (LON:RIO) RIO.AX , fell 2.7 percent and 2.4 percent, respectively.
BHP's fall comes as it picked up a 6.1 percent stake in SolGold PLC SOLG.L for $35.2 million, giving it a share in the promising Cascabel copper-gold project in Ecuador.
Blue Ocean Equities strategist Mathan Somasundaram was optimistic about the long-term benefits of the deal for BHP given that "buying assets in South America right now would be cheap because South American currencies are getting smoked".
"Copper is an asset, as a commodity it is not going to suddenly disappear. Whether you look at building electric cars or houses you still need cooper. So copper is going to be around into the future."
The market shrugged off Australia's rousing economic growth of 3.4 percent in the second quarter, fuelled by rapid population growth that spurred demand for homes and infrastructure. ASX's broad-based losses were deepened by a slide in financial stocks with the 'Big Four' banks hit by damaging revelations of misbehaviour in a high-level official inquiry into financial services misconduct.
Westpac WBC.AX fell 1.3 percent after it accepted a A$35 million ($25 million) fine on Tuesday for wrongly approving thousands of mortgages. Zealand's benchmark S&P/NZX 50 index .NZ50 turned away fractional gains earlier in the day to close down 0.7 percent, or 64.15 points to 9,228.0.
The losses were led by a 3.3 percent drop in a2 Milk Company ATM.NZ and a 2.7 percent fall from Fisher & Paykel Healthcare FPH.NZ .