Jeffrey McMahon, a former accountant for Arthur Andersen, was named the company's president and chief operating officer in January 2002.

On April 19, McMahon announced he will resign as president and COO effective June 1. He said Enron required "outside leadership" to successfully rebuild investor confidence and reorganize its finances. His replacement has not yet been selected.

McMahon was named Enron's chief financial officer in October 2001, following former CFO Jeffrey Fastow's dismissal. He joined Enron's finance department in 1994 and eventually took charge of the company's European financial operations.

McMahon also became treasurer during Fastow's tenure as CFO, and was among several senior-level employees that had complained to former CEO Jeffrey Skilling about Fastow's accounting practices.

McMahon started his career at Arthur Andersen in Houston where he worked as the audit manager of Andersen's Energy division.

In January, when restructuring specialist Stephen F. Cooper became interim CEO, Ray Bowen replaced McMahon as Enron's chief financial officer.

-- By Liz Harper, Online NewsHour