The 28-year-old British stock trader whose high-stakes gambles caused the collapse of England's oldest merchant bank is nowhere to be found. The Business Times in Singapore reported that Baring Brothers & Co. trader Nicholas William Leeson, who was working for the bank in Singapore, fled the country today, as the bank sought a criminal investigation. Leeson allegedly gambled more than the bank was worth on Tokyo stock futures, losing more than $1 billion when the market fell last week. That forced Baring to declare bankruptcy yesterday and triggered worldwide stock slides today. Baring investors and its U.S. subsidiaries may not suffer losses, but their deposits have been frozen. Leeson was dealing in stock derivatives, the same financial instruments that led to the bankruptcy filing last year by Orange County, Calif. TIME Brussels bureau chief Jay Branegan expects political pressure to strengthen derivative regulations, although he says tougher rules would not have protected Baring. "This was simply a rogue trader," says Branegan.