The local bourse has dropped for the fourth straight day as the United States draws ever closer to a catastrophic default on its debt.
The benchmark S&P/ASX200 index on Thursday suffered its biggest loss in nine weeks, falling to its lowest closing level in eight weeks.
It dropped 75.6 points, or 1.05 per cent, to 7,138.2, its lowest close since March 30 and biggest single-day drop since a 1.4 per cent fall on March 20.
The broader All Ordinaries on Thursday fell 76.2 points, or 1.03 per cent, to 7,316.7.
With the United States perhaps just a week away from hitting its $US31.4 trillion debt ceiling and being unable to pay its bills, Fitch Ratings placed its sterling AAA rating on "rating watch negative".
"The brinkmanship over the debt ceiling, failure of the US authorities to meaningfully tackle medium-term fiscal challenges that will lead to rising budget deficits and a growing debt burden signal downside risks to US creditworthiness," Fitch said.
Negotiators for President Joe Biden and US House Speaker Kevin McCarthy said they held a productive four-hour meeting at the White House, but a number of issues remained unresolved.
Tiger Brokers Australia chief investment officer Brett Reynolds said beyond the debt ceiling drama, lower resource prices were also weighing on the Australian market, as well as a big increase in domestic energy prices disclosed on Thursday.
Electric bills will rise up to 25 per cent under the decision by the Australian Energy Regulator, which Mr Reynolds noted would impact many households, hurting consumer spending.
"Further bad news for households is likely in the coming months," he added.
Tech stocks were the only sector in the green in midday, possibly boosted by a surge in Nvidia shares in after-hour trading.
The US semiconductor manufacturer's Nasdaq-listed shares soared by as much as 26 per cent after the company said it was boosting supply to meet surging demand for its artificial intelligence chips.
The ASX tech sector finished up 2.4 per cent, with circuit board software design company Altium up 4.3 per cent to a four-week high of $38.48 and cloud connectivity company Megaport up 12.8 per cent to a three-month high of $6.44.
The financial sector was the biggest loser, dropping 1.9 per cent as iron ore prices fell to a near six-month low of under $US100 a tonne on doubts about China's recovery.
BHP and Rio Tinto both retreated 1.6 per cent, to $42.15 and $105.40, while Fortescue Metals subtracted 3.2 per cent to $19.
Both goldminers and lithium producers were also well in the red, with Newcrest down 1.9 per cent and Pilbara dropping 1.3 per cent.
The Big Four banks all lost ground, with CBA down 2.2 per cent to $97.72, ANZ dropping 2.6 per cent to $23.35, Westpac retreating 1.6 per cent to $20.89 and NAB falling 2.1 per cent to $26.04.
Adbri jumped 21.9 per cent to a more than six-month high of $1.95 as executives delivered an upbeat financial year outlook at the cement manufacturer's annual general meeting in Sydney.
Strong demand from the mining, commercial and industrial sectors and cost increases implemented last year means net profit for the financial year that ended in April will be up significantly from last year, chief executive Mark Irwin said.
Treasury Wine Estate dropped 7.8 per cent to a nine-month low of $11.76 after the winemaker said its commercial wines - brands priced under $10 - were struggling and it was reviewing that portfolio.
Costa Group rose 6.7 per cent to a two-week high of $2.54 after the fruit and vegetable grower's interim chief executive told shareholders at its AGM its outlook looked bright after a challenging few years.
After impacting growing conditions for three years, La Nina ended in March; elevated cost pressures are moderating; and backpackers have returned, easing labour shortages.
It's also shaping up to be an "exceptional year" for Costa's blueberry crop operations in Morocco and China, Harry Debney said.
The Australian dollar was buying 65.34 US cents, from 65.72 US cents at Wednesday's ASX close.
ON THE ASX:
* The benchmark S&P/ASX200 index finished Thursday down 75.6 points, or 1.05 per cent, at 7,138.2.
* The broader All Ordinaries dropped 76.2 points, or 1.03 per cent, to 7,316.7.
CURRENCY SNAPSHOT:
One Australian dollar buys:
* 65.34 US cents, from 65.72 US cents at Wednesday's ASX close
* 91.09 Japanese yen, from 91.26 Japanese yen
* 60.93 Euro cents, from 61.07 Euro cents
* 52.94 British pence, from 52.84 British pence
* 107.28 NZ cents, from 107.18 NZ cents
