NEW YORK (Bloomberg) — Las Vegas Sands Corp., billionaire Sheldon Adelson's casino company, plunged in New York trading after saying it may default on debt and face bankruptcy.

The casino owner, which had $8.8 billion in long-term debt at the end of June, said in a regulatory filing yesterday that it probably won't meet the requirements of some loans unless it cuts spending on development projects, boosts earnings at its Las Vegas Strip casinos and raises more capital.

The reversal of fortune is a black eye for the 75-year-old Adelson, who was once America's third-richest man on the strength of his Las Vegas Sands holdings. The Las Vegas-based company's dwindling cash flow is threatening $16 billion worth of developments in Macau, China, and Singapore, where Las Vegas Sands is building resorts to cater to wealthy Asian gamblers.

"They need to raise money," said Keith Foley, a New York-based analyst at Moody's Investors Service Inc. "It's getting to the point where they need to do something now."

Las Vegas Sands had tumbled 91 percent before yesterday as investors dumped the stock, worried that falling casino winnings and the global financial meltdown would leave the company without enough cash to pay for expansion projects or cover its loans.

Spending declines on the Vegas Strip and restrictions on visas in Macau have stemmed the flow of cash into Las Vegas Sands. Yesterday's admission came after Adelson, who holds a stake of more than 64 percent, invested an additional $475 million in September to avoid violating the terms of a loan, and hired an unidentified investment bank to raise more capital with his help.

Las Vegas Sands said it doesn't expect to meet a maximum leverage ratio covenant in the fourth quarter. That would trigger defaults that might force the company to suspend development projects and "raise a substantial doubt about the company's ability to continue as a going concern."

"Sheldon still has considerable resources, and we doubt he will sit on the sidelines and watch LVS go bankrupt," Robert LaFleur at Susquehanna Financial Group LLLP, said today in a client note he titled "Scary Post-Halloween 8-K Filing." "The question is how much dry powder does he have, and what can he do?"

In a July conference call, Adelson suggested he would step in to help the company with any financing it might need, saying a friend described him as "the tallest person I know when you stand on your wallet".

"And I'm saying right now, the company will not have liquidity problems," he said at the time.

Adelson founded the Comdex computer expo in 1979, later selling the business and using the proceeds to build the Venetian Resort Hotel Casino in Las Vegas. The filing sparked new concerns that Las Vegas Sands won't finish Singapore's first casino or a 20,000-room complex of hotels and casinos in Macau. The Chinese territory overtook the Vegas Strip as the world's biggest gambling market in 2006.

Should Sands fail to raise capital "we would need to immediately suspend portions, if not all, of our ongoing global development projects and consider other alternatives," the company said in the filing.

Las Vegas Sands owns the Venetian and Palazzo casino resorts on the Las Vegas Strip, plus the Macau Venetian, Sands and Four Seasons.