Star Cruises, the world's third-largest cruise line, is reviewing its planned investment in a HK$4.7 billion Macau casino project to be operated by gaming magnate Stanley Ho Hung-sun. Yesterday's announcement by the Hong Kong-listed unit of Malaysia's Genting Group came as Singapore's casino regulator confirmed it was investigating the partnership deal, which would also see Mr Ho and his fourth wife Angela Leong On-kei acquire a 4.6 per cent stake in Star Cruises through a share placement. The casino would operate under Sociedade de Jogos de Macau (SJM), Mr Ho's licensed gaming company. 'The company is reviewing the structure in relation to its [Macau] investment,' Star Cruises said yesterday in an announcement to the stock exchange. It delayed sending a circular until February 28. Star Cruises shares soared 48 per cent after the Macau project was announced on January 23 but have since fallen 26 per cent on regulatory uncertainties. Under Singapore's Casino Control Act, the gaming regulator has the right to investigate casino licence holders and their associates, and has the power to amend or ultimately block any venture, including overseas projects, whose partners it deems 'unsuitable'. Star Cruises and sister firm Genting International in December won the right to build and operate a US$3.4 billion casino resort on Sentosa island. It is the city state's second gaming licence. 'The Casino Regulation Division is seeking clarification from Star Cruises/Genting International about the share placement and the other deals in Macau,' James Chan Yong Kiat, a manager at the regulator, said on Tuesday. He declined to elaborate. The Resorts World Macau project calls for a boutique hotel and an SJM-run casino to be built on an 87,000 square foot patch of reclaimed land across from the newly opened Wynn Macau. Star Cruises would own 56 per cent and Genting 19 per cent. Local partners Yany Kwan Yan-chi and his brother Kwan Yan-ming, who together contributed a portion of the land, would take up the remaining 25 per cent interest. Under the terms of the Macau deal announced last month by Star Cruises, the agreement with Genting will terminate automatically if both companies fail to obtain approval from the 'relevant regulators' by March 19. Citing 'regulatory uncertainty surrounding the project's ability to proceed in its current form', Merrill Lynch analyst Sean Monaghan on Monday revised his fair value estimate for Genting's 19 per cent stake in the Macau casino to zero from HK$1.5 billion. If the Macau venture fails to proceed, the Genting units will forfeit a HK$153.56 million deposit on the land, plus about HK$60 million consisting mainly of finders' fees paid to consultants who helped put the deal together.