Crown Resorts Ltd posted an annual loss on Monday, hurt by lockdown-led casino closures and regulatory costs, and said it was no longer talking to Oaktree Capital Group over the private equity giant's proposal to buy a stake.

Australia's largest casino operator is grappling with a series of challenges, ranging from virus-led lockdowns to regulatory scrutiny that has cost its Sydney casino its licence and threatened the ones at Melbourne and Perth.

Travel restrictions in the country have also made it difficult for overseas gamblers, especially from China, to visit its casinos and spend more.

"Looking ahead, COVID-19 continues to create uncertainty, with variable operating restrictions remaining a feature of everyday life and likely to continue to materially influence business performance," said interim Chairwoman Jane Halton.

Crown has also been under intense regulatory scrutiny as it tries to convince authorities that it can rebuild its culture after a Sydney inquiry in February found the company allowed money laundering on its premises for years.

An inquiry into its Melbourne casino - which generates three-quarters of its profit - will end in October, while a separate one into its Perth casino has been extended to March 2022.

The uncertainty caused Star Entertainment Group in July to withdraw a A$9 billion buyout proposal.

A separate A$3 billion Oaktree proposal was pitched as an option to bankroll a buyout of a part of billionaire James Packer's stake.

On Monday, the company reported a net loss of A$261.6 million ($191.33 million) for the year ended June, compared with a A$79.5 million profit a year earlier.