* Materials and banks drive Aussie shares lower
* Materials lower on fall in commodities prices
* Banks slip ahead of quarterly update
* NZ falls on materials and health care stocks
By Aditya Soni
Aug 13 (Reuters) - Australian shares dipped on Monday as banks declined ahead of quarterly performance updates later in the week, while the escalating trade dispute between the United States and China curbed commodities prices.
The S&P/ASX 200 index .AXJO fell 0.5 percent or 29 points to 6,249.40 by 0200 GMT. The benchmark declined 0.3 percent on Friday.
Materials stocks, especially miners, set the bearish trend as global trade tensions continued to drain demand for copper, while Dalian iron ore futures DCIOcv1 slipped 0.6 percent.
Global miner BHP BHP.AX dipped 0.8 percent to a more than one-week low, while its spin-off South32 Ltd S32.AX dropped 2.9 percent.
Financials .AXFJ declined 0.4 percent, pushing the benchmark lower.
Investors would be focusing on updates from three of the country's "big four" banks this week after top lender Commonwealth Bank of Australia CBA.AX warned of slower mortgage growth and reported on Wednesday its first fall in annual net profit in almost a decade . results highlight a challenging year for Australia's lenders as they faced hefty penalties for malpractice and a heavy blow to their reputations from a public inquiry into financial sector misconduct.
James McGlew, executive director of corporate stockbroking at Argonaut said there were still some significant tailwinds propelling Australian banks, including "that they still have very good dividends".
CBA was trading 0.8 percent lower, while National Australia Bank Ltd NAB.AX fell 1.1 percent to near a two-week low.
Conversely, energy stocks rose, braking the benchmark's slide after crude oil prices rose more than 1.0 percent on Friday as U.S. sanctions against Iran looked set to tighten supply. Petroleum Ltd WPL.AX rose about 1 percent and was the biggest boost to the benchmark, while Santos Ltd STO.AX firmed 1.5 percent.
Santos said a fourth gas rig had started operations at the Cooper Basin site in South Australia to feed the gas-starved east coast market. The rig will drill eight wells by year-end. guidance upgrade from health insurer NIB Holdings Ltd NHF.AX and strong earnings from electronics retailer JB Hi-Fi Ltd JBH.AX also provided support to the main index.
NIB Holdings surged 12.5 percent to a near five-month high after raising its underlying operating profit for fiscal 2018 to about A$184.0 million ($133.99 million), versus previous guidance of minimum A$165.0 million. shares of retailer JB Hi-Fi jumped 1.6 percent after it said annual underlying profit rose 12.3 percent, beating expectations, as it took into account a full year's contribution from its home appliances business. the Tasman Sea, New Zealand's benchmark S&P/NZX 50 index .NZ50 slipped 0.4 percent or 32.88 points to 8,978.59.
Health care stocks and materials drove the losses, with Ryman Healthcare Ltd RYM.NZ falling 1.2 percent, while Fletcher Building Ltd FBU.NZ dipped 1.7 percent.