A 79-year-old Palm Beach socialite pleaded guilty Tuesday to hiding $43 million in an overseas bank account, the largest amount prosecuted since the Justice Department cracked down on the Swiss bank UBS two years ago.

Mary Estelle Curran pleaded guilty to filing false tax returns, admitting to Senior U.S. District Judge Kenneth Ryskamp in West Palm Beach that she failed to report her offshore accounts from 2001 to 2007.