Britain's financial watchdog slapped a 17.5 million pounds ($27 million) fine on Goldman Sachs on Thursday for inadequate disclosure of a U.S. probe into the Wall Street powerhouse. The fine -- one of the biggest ever imposed in Britain -- was related to Goldman's troubled Abacus mortgage-security product, which resulted in the investment bank being investigated by the U.S. Securities & Exchange Commission (SEC). In July, Goldman agreed to pay $550 million to settle civil fraud charges over how it marketed the Abacus subprime mortgage product, ending months of negotiations that rattled the bank's clients and investors.