Leonard Litwin (born 1915) is an American real estate developer who, through his company, Glenwood Management, specializes in residential construction. His firm currently owns and operates approximately 23 buildings in Manhattan. [1] In 2006, Litwin ranked number 374 on the Forbes 400, with a net worth of approximately $1 billion. [2] He was named as one of the holders of an account with alleged Ponzi scheme firm Bernard L. Madoff Securities in a court filing in February, 2009.