"We in the financial products unit have been betrayed by AIG and are being unfairly persecuted by elected officials," wrote DeSantis. "In response to this, I will now leave the company and donate my entire post-tax retention payment to those suffering from the global economic downturn."
He added: "I take this action after 11 years of dedicated, honorable service to AIG. I can no longer effectively perform my duties in this dysfunctional environment."
AIG has been heavily criticized since it awarded $165 million in bonuses this month. The payments, to keep valued employees from quitting, were made whether the employee had a great year or a terrible one. They were given to employees of the financial products division, which issued credit default swaps that helped sink AIG.
Liddy "deeply appreciates the frustration expressed in this letter and believes that the recent vilification and harassment of AIG employees is grossly unfair and unwarranted," wrote AIG spokesman Mark Herr.
Attempts to reach DeSantis were unsuccessful.
Two days after AIG received its first injection from the government in mid-September, AIG named Liddy, former chairman of Allstate Corp., as chairman and chief executive succeeding Robert Willumstad, who stepped down after three months on the job.
AIG came close to collapsing last September because it had gotten heavily into the business of insuring mortgage-backed securities.
The government has given AIG $182.5 billion to keep it afloat and taken an 80 percent stake in the company.
