The S&P/ASX200 fell 12.6 points on Monday, down 0.14 per cent, to 8,816.1, as the broader All Ordinaries lost 16.1 points, or 0.18 per cent, to 9,031.2.
A dip in oil prices wasn't enough to send the bourse higher, as the US and Iran agreed to a road map towards a final peace deal within 60 days.
"The S&P/ASX200 index spent much of today treading water, finishing little changed as investors weighed a tentative Strait of Hormuz agreement against the reality that geopolitical deals are often signed faster than they are honoured," Global X ETFs senior product and investment strategist Marc Jocum said.
Crude prices are back to where they were mid-last week, despite spiking overnight after US President Donald Trump threatened further attacks, prompting Iran to claim it had re-closed the Hormuz Strait.
Financials carved a 0.5 per cent improvement, led by strong insurer performances, while the big four banks eked modest gains ahead of key inflation and jobs data due later in the week.
The materials sector was sluggish, as BHP continued its slump since flagging a cost blowout and impairment charge relating to its Jansen potash project in Canada.
Fellow mega miners Fortescue and Rio Tinto were also in the red as copper and iron ore futures struggled to rebound from recent weakness.
Gold stocks helped counterbalance some of the weakness in miners elsewhere, the All Ordinaries gold sub-index advancing 1.8 per cent as the precious metal recovered to around $US4,200 ($A5,999) an ounce.
IT stocks weighed on the local exchange, down 4.2 per cent as WiseTech shares plummeted 16 per cent on reports the Australian Federal Police were investigating executive chair and billionaire co-founder Richard White over claims he exploited a woman's financial and immigration status.
Both WiseTech and the AFP declined to comment on the matter, and AAP is not suggesting of any wrongdoing by Mr White, only that the allegations have been reported.
"I feel for WiseTech, I feel like they just can't seem to shake the fallout from the former CEO, now executive chairman, but it just feels like we've got to the point where you need to cut the umbilical cord there and say goodbye to him once and for all, for the sake of everybody," Â IG market analyst Tony Sycamore told AAP.
In other company news, Humm shares lost more than a fifth of their value after Credit Corp ditched plans to buy the consumer credit fintech.
Inghams lost almost five per cent after locking down its farms and processing operations in Western Australia, following the first documented case of H5N1 bird flu on Australian soil.
The Australian dollar is buying 70.04 US cents, down from 70.12 US cents on Friday at 5pm.
ON THE ASX:
* The S&P/ASX200 fell 12.6 points, or 0.14 per cent, to 8,816.1
* The broader All Ordinaries lost 16.1 points, or 0.18 per cent, to 9,031.2
One Australian dollar trades for:
* 70.04 US cents, from 70.12 US cents at 5pm AEST on Friday
* 113.27 Japanese yen, from 113.08 Japanese yen
* 53.02 euro cents, from 61.28 euro cents
* 53.02 British pence, from 53.12 British pence
* 122.25 NZ cents, from 112.14 NZ cents
6°C