Lay transformed Enron from an interstate natural gas pipeline company into an international power conglomerate, with stated profits over $33 billion and operations in over 30 countries. Lay was widely considered the wizard of global energy markets after Enron demonstrated it could yield massive profits from an otherwise dull business.

Some also viewed Lay as a pioneer in energy market deregulation in the U.S. Lay consulted with members of Vice President Dick Cheney's National Energy Policy Development Group at least six times since February 2001 and advised other lobbyists and lawmakers involved in regulating energy markets.

Lay was also a major political campaign contributor to candidates in both the Democrat and Republican parties, although the majority of the candidates Lay supported are from Republican party and often from Texas.

Lay grew up in the Ozark Mountains of Missouri, where his father sold farm equipment and served as a Baptist minister. Lay won a scholarship to the University of Missouri, where he earned both Bachelor's and Master's degrees in economics. He began working for Exxon as a corporate economist in 1965, while also working toward a Ph.D. in economics from the University of Houston.

In the mid-1960s, he served briefly as a Navy officer and later as deputy undersecretary of the U.S. Department of the Interior.

Before taking Enron's helm, Lay led several other energy companies, including the Florida Gas Company, the Transco Energy Company, and the Houston Natural Gas.

Lay has served on the boards of directors of Compaq Computer Corporation, Eli Lilly and Company, and Trust Company of the West. In 1998, Lay won the Horatio Alger Award for Distinguished Americans and was inducted into the Texas Business Hall of Fame.

-- By Liz Harper, Online NewsHour