As widely expected, Stan O’Neal is out as chairman and chief executive officer of Merrill Lynch & Co. The investment banking giant said O’Neal “decided to retire” from the company that he has served as CEO since December 2002, and joined 21 years ago.

As a result, the board elected Alberto Cribiore as interim non-executive chairman on Tuesday.

But that wasn’t the end of Tuesday’s announcements about Merrill. CNBC reported that Merrill’s Chief Financial Officer Jeffrey Edwards, who is responsible for the firm’s risk management, also offered to resign. The turmoil in the executive suite stems from the company’s announcement last week that it would take more than $8 billion of write-offs in the third quarters due in large part to its exposure to mortgages and other securities that have collapsed in value.

Merrill’s board rejected Edwards’ offer, according to the news report.

Edwards is not an archetypical bean counter. To start, he holds an undergraduate degree in physics from Haverford College and an M.B.A from Harvard, and rose through the Merrill ranks as a Wall Street banker. Indeed, Edwards joined Merrill in 1987 as an associate in investment banking, and is currently responsible for the firm’s market and credit risk management, which includes the collateralized debt obligation portfolio, which accounted for much of the firm’s losses, according to Reuters.

Edwards is also responsible for treasury, financial reporting and controls, corporate and strategic planning, internal audit and tax policy, as well as regulatory reporting and supervision. Prior to assuming this role in March 2005, Edwards served as head of investment banking for the Americas region. In this position, he was responsible for Investment Banking origination activities for corporate, financial and sovereign clients in the United States, Canada and Latin America, across all capital markets and advisory products.

From 2003 to 2004, Edwards served as head of Global Capital Markets & Financing, with responsibility for all capital-raising activities for the firm’s issuer clients, including equity and debt capital markets, corporate finance and equity and debt derivatives origination. Before that, Edwards was co-head of Global Equity Markets, with responsibility for the firm’s equity markets activities globally, including trading, underwriting and sales of all equity and equity-linked securities.