Sociedade de Jogos de Macau Holdings (SJM) is due to list on Hong Kong's stock market on Thursday, but Ho's estranged sister Winnie has made a last-ditch legal move to block the initial public offering.

The move is the latest in a long-running legal feud between the two over who should control and profit from the gaming empire. There are now 35 pending legal actions in Macau and five in Hong Kong.

'What is being challenged is whether the company has any assets at all,' Mr Martin Lee, her lawyer, told Hong Kong's High Court.

'(Investors) may end up investing in a company that owns a casino in the air,' Mr Lee said.

Ms Winnie Ho has called for a full judicial review of decisions made by the stock exchange and the Securities and Futures Commission with respect to the IPO, according to the court documents.

She said the listing was illegal and 'contrary to the public interest and the longstanding policy of the Hong Kong government not to promote gambling'.

SJM had initially hoped to raise one billion US dollars in an IPO in January, but postponed the plan due to a weak Hong Kong market.

It then placed its shares on subscription offer from June 26 to July 2, and reports said it had raised less than 500 million US dollars (S$681.7 million).

SJM hoped to use the cash raised to fund its plan to compete with the newcomers to Macau's gaming industry, which overtook the Las Vegas Strip in 2006 in revenues.

Mr Ho for decades held a monopoly on casinos in the former Portuguese colony, but the market was liberalised in 2002, allowing huge US operators like Las Vegas Sands and Wynn Resorts to eat away at his market share.

Ms Winnie Ho worked for the firm's parent company STDM for 25 years until 2002 and still retains a stake in the company, although Stanley Ho has tried to eject her as a shareholder since the spat began.

Judge Anselmo Reyes said he would make his decision on the court bid on Wednesday. -- AFP