SYDNEY (Reuters) -Star Entertainment Group's shareholders approved on Wednesday an A$300 million ($195 million) rescue package that will allow the embattled Australian casino group to remain operational, according to a company presentation.

The rescue bid is being led by U.S. casino firm Bally's Corp and the Mathieson family, which is Star's largest existing shareholder.

The proposal put to shareholders at a Sydney meeting was approved by more than 98% of investors' proxy votes, according to company slides shown at the event that was live-streamed. A final result of the vote will be announced later on Wednesday.

Australia's second-largest casino operator after Blackstone-controlled Crown Resorts, Star has been struggling to stay afloat amid a growing debt crisis and regulatory investigations over the past two years.

The rescue deal consists of multi-tranche convertible notes and subordinated debt instruments, and after the notes are converted, Bally's and the Mathieson family will control around 56% of Star's issued capital.

Star chairman Anne Ward said the company had no other option than to support the Bally's-led bid after interest from Oaktree and Salters Brothers collapsed earlier this year.

"The strategic investments ... provide cash funding and assist Star's ability to continue as a going concern, helping to avoid outcomes such as voluntary administration, which is likely not in the best interests of shareholders," Ward told the meeting.

Star said in March it would sell half of its A$3.6 billion Queen's Wharf project in Brisbane to Hong Kong companies Far East Consortium International and Chow Tai Fook Enterprises for just A$53 million. It has also sold a theatre attached to its main casino in inner-city Sydney as part of its efforts to stay afloat.

Bally's owns 19 casinos across 11 U.S. states, according to its website, and the Star investment is its first in Australia.

($1 = 1.5394 Australian dollars)

(Reporting by Scott Murdoch; Editing by Tom Hogue and Muralikumar Anantharaman)