SYDNEY (Reuters) - Billionaire James Packer has resigned 22 Australian company directorships in the last few weeks and no longer holds any board seat in his home country, corporate records show, signaling his almost full retreat from public business life.

FILE PHOTO: Australian Businessman and founder of Australia's Crown Ltd, James Packer walks to the stage at an evening business event in Sydney October 25, 2012. REUTERS/Tim Wimborne/File Photo/File Photo

The major shareholder of casino operator Crown Resorts Ltd CWN.AX cited mental illness as the reason for his quitting that firm's board in March, following a tumultuous period in his life, which included a break-up with singer Mariah Carey and the failure of Crown's expansion strategy.

He quit the board of his private company Consolidated Press Holdings (CPH) on June 27, and corporate records show he resigned from 19 other directorships on the same day, plus another two since.

Packer, whose net worth is estimated by Forbes at $4.1 billion, has quit 24 Australian company boards this year.

“The changes are largely administrative in nature and reflect attempts to modernize and simplify the corporate structures,” a spokesman of Packer’s flagship CPH said by email on Thursday.

His retreat is all the more remarkable because for generations, and most of the 20th century, the Packer family has been a fixture of Australia’s media business scene.

The 50-year-old James is one of Australia's highest profile businessmen and a household name who has previously served on the boards of some of the country's biggest companies, from Qantas Airways Ltd QAN.AX to Nine Entertainment Co Holdings Ltd NEC.AX and Seek Ltd SEK.AX, where he was an early investor.

Packer’s father, Kerry, inherited media interests from his own father, Frank, in 1974 and built them into a publishing and television empire - which James sold a decade ago in order to form Crown, a casino firm.

He built it up before quitting as a director in 2015 amid heavily publicized personal upheaval including a brief engagement to Carey.

Packer rejoined Crown’s board a year later during a period of turmoil for the company when a dozen and a half of its employees were jailed in China for alleged breach of gambling marketing laws there.

“Mr Packer is suffering from mental health issues. At this time he intends to step back from all commitments,” CPH had said in March, when Packer quit Crown’s board.

The Australian newspaper, which first reported Packer’s string of resignations, said he remains a director of CPH’s parent company, Consolidated Press International Holdings Limited, domiciled in the Bahamas.