An American Express Co. subsidiary has agreed to a $50 million fine -- the largest penalty ever assessed against a financial institution for drug money-laundering charges -- as part of the settlement of a massive case, Justice Department officials announced today. American Express Bank International will give up $33 million seized by U.S. Customs agents in 1992 and $7 million made in money-laundering transactions on behalf of a Mexican drug organization. (Two bank officials were convicted on laundering and fraud charges earlier this year.) TIME assistant editor Bernard Baumohl, who covers business, says the troubles are part of a domino effect in law enforcement following the world's largest international banking scandal -- the Bank of Credit and Commerce International (BCCI). "The Justice Department has been aggressively trying to find a weak link in the international money-laundering business, and the weak link would be in any international bank," he says.