Okada is engaged in a public spat with Universal, whose board ousted him as chairman in 2017 and accused him of misappropriating $20 million, which the billionaire denied.

Tiger Resort Asia Ltd, Universal's subsidiary, agreed to acquire a majority stake in a Manila listed company in September, paving the way for its own backdoor listing. Tiger owns the operator of the $2.4 billion Okada Manila integrated casino-resort.

"The backdoor listing is not authorized and is opposed by the casino magnate, the true and legal beneficial owner of controlling shares, and Chairman or Sole Director, in all Okada Companies," Okada's lawyers said in a January 11 letter to the PSE, which was sent to the media.

The PSE should disallow the backdoor listing because "there exists, at bare minimum, a serious issue as to whether Fujimoto et. al. are legitimate directors/officers of Tiger, and the rest of the Okada Companies, that can act for and on behalf of said Companies,” the lawyers said, referring to Universal President Jun Fujimoto.

Officials of the stock exchange, Universal and Tiger were not immediately available for comment. It is a public holiday in Japan on Monday.

A Philippine court earlier this month ordered the arrest of Okada, who is facing fraud charges. In August, he was arrested in Hong Kong because of multiple corruption-related charges and is currently on bail.

(Reporting by Neil Jerome Morales; Additional reporting by Elaine Lies in Tokyo; Editing by Muralikumar Anantharaman)