Australian shares fell on Wednesday's close on concerns from US firms that president-elect Trump's tariffs could raise prices.

The S&P/ASX 200 Index fell almost 0.6% or 47.7 points to close at 8,326.3.

US corporations, including the nation's largest retailer, Walmart, suggested that prices could increase if tariffs rise, Reuters reported.

Since the beginning of September, executives from nearly 200 companies have addressed price increases as Trump has vowed to make tariffs central to his economic agenda, the report added.

Asian markets were also cautious ahead of earnings results from the American technology company Nvidia.

Nividia's $3.6 trillion stock can move almost 9% in either direction after its third-quarter results, Reuters added.

On the domestic front, Australia's Leading Index improved to positive 0.3% in October from negative 0.2% in September, according to a report by the Melbourne Institute. This is the first time the measure has shown a clear above-trend result since November 2023 and is the strongest level since July 2022, when the index was at positive 0.6%

Australian consumers' spending growth slowed in the third quarter, with a notable decline among the younger age group, according to CommBank's Cost of Living Insights Report. Total spending across the Australian economy rose 1.5% year on year in the September quarter, compared with the 2.2% increase recorded in the year-ago period and the 2.8% inflation rate in the third quarter.

In company news, Amcor (ASX:AMC) plans to merge with fellow packaging company Berry Global via an all-stock deal with Berry shareholders to receive about 7.3 Amcor shares, the companies said in a joint statement.

PWR Holdings (ASX:PWH) issued a net profit after tax forecast of AU$3.2 million to AU$3.7 million for the first half of fiscal 2025, down from the reported AU$9.8 million a year earlier. The company's shares fell almost 25% at market close and earlier hit their lowest since July 2022.

Nick Scali (ASX:NCK) experienced shipment delays for its products at ports after one of its customs and freight forwarding agents entered administration. The delays add a risk to the company's net profit guidance of AU$30 million to AU$33 million for the first half of fiscal 2025, as per the filing. The company's shares were down almost 2% at market close.