* AU benchmark loses over $25 bln in market value on day
* Mining and energy units weigh most in main index
* Tech stocks also stumble (Updates to close)
By Devika Syamnath
August 5 (Reuters) - Mining stocks led Australian shares to their worst session in over seven months on Monday, with investors slashing riskier positions as the growing trade war between the United States and China revived worries about weaker global growth.
The S&P/ASX 200 index <.AXJO closed 1.9%, or 128.3 points, lower at 6,640.3, its fourth session in the red and the largest one-day decline since last December.
Resource stocks, Australia's biggest export sector, bore the brunt of the benchmark's .AXJO A$37.77 billion ($25.58 billion) loss in market value since Friday's close. (Calculations based on Refinitiv Eikon data)
Investors have dumped riskier assets since U.S. President Donald Trump abruptly declared late last week that he would slap 10% tariffs on $300 billion in Chinese imports, snuffing a month-long trade truce and prompting China to warn of retaliation. MKTS/GLOB
China is the biggest buyer of Australian exports. On Monday, the world's no. 2 economy let its currency slide past the key 7-per-dollar level for the first time in more than a decade. (People's Bank of China) weaponizes the renminbi...the boost to China's export sector from currency depreciation is worth attracting the ire of the Trump," said Capital Economics in a note.
The world's biggest miner BHP Group BHP.AX shed 3.6% to close at a near two-month low, while smaller peer Fortescue Metals Group FMG.AX tumbled 7.2%.
Heavyweight banking units .AXFJ lost 1.5%, with the "big four" banks giving up between 0.8% and 1.7%.
Australian oil and gas companies .AXEJ also declined, with Santos STO.AX giving up 2.4%. However, Oil Search OSH.AX closed 2.9% higher after the Papua New Guinea government signalled its backing for a liquefied natural gas deal in which the company is a partner. technology stocks .AXIJ saw their worst session since February 2016, and data solutions provider Appen APX.AX was the top loser on the main index. Declines followed sharp losses for U.S. peers on Friday as the trade war escalated. the economic front, focus will be on the central bank policy reviews in Australia and New Zealand this week, and on Chinese trade and inflation data.
In New Zealand, the benchmark S&P/NZX 50 index .NZ50 finished 0.9% lower at 10,766.03.
Dairy products makers A2 Milk Co ATM.NZ and Synlait Milk SML.NZ led losses, giving up 3.3% and 3.7%, respectively.
($1 = 1.4767 Australian dollars)