* Landing unable to reach chairman since early Thursday
* Shares drop as much as 33 pct before closing down 16 pct
* Philippines halted Landing casino project this month (Updates shares; adds comment from Cambodian immigration, context on Chinese government anti-corruption drive)
HONG KONG, Aug 24 (Reuters) - Landing International Development Ltd said it has been unable to contact its chairman and controlling shareholder for over a day, sending its shares plummeting and wiping off almost half of the casino operator's market value in a two-day selloff.
The announcement comes just weeks after authorities halted Landing's $1.5 billion casino project in the Philippines, in a move which likewise sent the firm's stock tumbling.
The management crisis is the latest at a Hong Kong-listed firm since the former chairman of Huarong International Financial Holdings Ltd, Lai Xiaomin, resigned in April after becoming the subject of an anti-corruption investigation.
At Landing, shares plunged on Thursday before the casino operator requested a trading halt pending an announcement.
In a statement late on Thursday, Landing said it had been "unable to contact or reach" Yang Zhihui since earlier that day, adding its operations and finances were normal. It did not state whether it had reported the chairman as missing to the police.
A spokeswoman told Reuters on Friday that the firm was still attempting to contact the chairman. She declined to elaborate beyond the content of Landing's statement.
Landing shares resumed trading on Friday, falling as much as 33 percent before closing down 16 percent. The stock was worth HK$20 in March but has sunk to a 16-month low of HK$3.15.
The firm now has a market value of about HK$11 billion ($1.40 billion), with Yang owning 50.48 percent of its issued share capital, showed data from Thomson Reuters Eikon.
Yang was involved in property development in China's eastern Anhui province before joining Landing in 2013. Casino executives said he has a close relationship with Macau junket operators, who facilitate the VIP high-roller gambling business.
He also has business ties with Huarong, Chinese publication Caixin reported on Friday. Huarong did not respond to a Reuters request for comment.
Huarong's Lai is among a number of executives to be investigated under a government anti-graft campaign. Authorities have also detained executives in an effort to curb excessive financial risk, with a probe into the former chairman of Anbang Insurance Group Co Ltd, Wu Xiaohui, ending in a jail sentence.
Caixin also reported that Yang had been detained at a Cambodian airport. The chief of Cambodia's Immigration Investigation Bureau, General Uk Haiseila, told Reuters on Friday that no Chinese citizen named Yang had been arrested.
Landing listed the same year Yang joined the firm, taking over listed Greenfield Chemical Holdings Co in a deal facilitated by Kingston Securities, a financial services firm headed by Hong Kong billionaire Pollyanna Chu.
It opened its first self-built casino on South Korea's Jeju island in February, and in July was granted a license to build a casino in Manila's Entertainment City.
Shortly after breaking ground in Manila on Aug. 7, however, a presidential spokesman said the casino would be canceled because Landing's lease was unfavorable to the government. ($1 = 7.8494 Hong Kong dollars)
(Reporting by Farah Master; Additional reporting by Prak Chan Thul; Editing Christopher Cushing)