Thousands of workers at embattled Star casinos have been saved after a United States gaming giant swooped in to take on the challenge of reviving the flailing business.

Star Entertainment has signed a $300 million rescue package with Bally's Corporation to save the business from administration.

In a late-night update to the ASX on Monday, Star Entertainment revealed Bally's would pay $100 million by Wednesday to keep auto yomi casino login doors open across Brisbane, the Gold Coast and Sydney.

Bally's, which owns and manages 19 casinos in the US, will get a 56.7 per cent stake in The Star.

The remaining funds will be paid either following a shareholder vote or split into two payments before October 7.

The Star is exploring a possible injection of $100 million by its largest shareholder Bruce Mathieson, which would result in Bally's contribution dropping to $200 million.

The group's board would seek for all shareholders to agree unanimously to the deal, which was in their best interests and unlock the remaining Bally's contribution, the ASX statement said.

Bally's started in 2004 by acquiring a British horse and greyhound racing company and its tracks before it began investing in casinos.

Over the past decade, the giant has bought out and revamped casinos across 11 US states, recently acquired a UK casino and is building a venue in Chicago.

The business has invested in digital gaming and sports betting, acquiring free-to-play online games, fantasy sports, online casinos and launching a streaming sports service.

Bally's says its proven track record of revitalising businesses means there is a "brighter future" for the Australian operator.

"This transaction provides Bally's the opportunity to infuse The Star with what it needs to regain its position as Australia's pre-eminent gaming destination," said chairman Soo Kim, whose hedge fund Standard General took control of Bally's in a $US4.6 billion deal.

The United Workers Union welcomed the deal for the 9000 employees across the group who could have been left high and dry if it collapsed.

"Any deal that promises to keep venues in Brisbane, the Gold Coast and Sydney operating as a going concern is a good result for The Star workers, their families and the communities they live in," the union's casinos director Andrew Jones said.

"The alternative without a sensible resolution was thousands of workers facing the unemployment queue."

The Star has been in a trading halt since the end of February after being unable to file its half-year financial report without a refinancing plan to save it.

The group has been on the brink of collapse for months but staved off administrators by offloading its 50 per cent stake in a new Brisbane precinct and getting a $250 million short-term bridging loan.

It has been seeking a rescue package to stay afloat, with the group most recently failing to secure $940 million from property development fund Salter Brothers Capital.

The casino group was once worth billions of dollars but has been slapped with fines of $210 million and licence suspensions after money laundering allegations.

A 2022 NSW inquiry found damning evidence of money laundering and counter-terrorism failings at the groups' Sydney casino while a 2024 probe found more breaches.

A Queensland inquiry found The Star encouraged people banned from gaming in Victoria and NSW to gamble at its casinos in the Sunshine State.