Louis Lowenstein, a Wall Street corporate lawyer who wrote financial tomes decrying the dangers of the Street's worst investment practices, died of pancreatic cancer Saturday at his home in New York. He was 83.

He was married for 56 years to Helen Udell Lowenstein, with whom he had three children, including Roger Lowenstein, a former reporter for the Daily Press' former afternoon edition, The Times-Herald. After leaving the Peninsula three decades ago, the younger Lowenstein went on to write The Wall Street Journal's "Heard on the Street" column. He became an author in his own right, with four books to his credit, including a best-selling biography of billionaire investor Warren Buffett.

The elder Lowenstein worked his way through Columbia Law School after returning home from a stint in the Navy as a lieutenant aboard an LST during World War II.

He was founding partner at the law firm of Kramer, Levin, Naftalis & Frankel, then left the firm to become president of Supermarkets General Corp., a $2 billion diversified retailer. After leaving corporate life, Mr. Lowenstein became the Simon H. Rifkind Professor of Finance and Law at Columbia Law.