Australia's stock market opened the new financial year with declines, as key banking shares and a decision limiting supermarket expansion pressured the benchmark ASX 200. On the first trading day, the ASX 200 fell 55.80 points, or 0.64 percent, closing at 8722.90. The broader All Ordinaries index declined 54.80 points, or 0.61 percent, to 8931.40. Concurrently, the Australian dollar continued its downturn, trading at 68.89 US cents.

Seven of the 11 sectors posted losses, with the consumer staples sector among the hardest hit. Woolworths shares decreased by 1.80 percent to $39.31, while Coles experienced a sharper drop of 4.19 percent, closing at $23.35. A2 Milk also fell 1.87 percent to $7.34.

Coles's share price decline was linked to the Australian Competition and Consumer Commission’s (ACCC) decision to block the supermarket’s planned expansion in Kalgoorlie, Western Australia. The company also confirmed reports that it is in talks with telecommunications firm TPG to potentially acquire Greencross Pet Wellness Company, a move that added to investor uncertainty.

The banking sector also weighed on the market amid data indicating house prices experienced their largest monthly fall since 2022. Major banks suffered notable declines: Commonwealth Bank dropped 2.36 percent to $160.73; Westpac fell 1.45 percent to $34.70; National Australia Bank lost 2.30 percent to $36.99; and ANZ declined 2.49 percent to $34.47.

In contrast to the downward trend in consumer staples and banking, the healthcare sector showed resilience. CSL, a leader in vaccine production, gained 3.16 percent to reach $118.37. However, not all healthcare stocks moved higher, as Sigma Healthcare fell slightly by 0.36 percent to $2.74.

Overall, market movements reflected a cautious investor sentiment influenced by regulatory actions and economic indicators related to the housing market, signaling potential challenges as the financial year commenced.