CIA Director David Petraeus has resigned after admitting to an extramarital affair.

The shock resignation happened Friday afternoon and took Washington by surprise NBC News reports that Mike Morrell, the deputy CIA director, will be offered the job.

Petraeus is a highly decorated general widely praised for his leadership in the Afghan and Iraq conflicts.

In his letter he wrote:

HEADQUARTERS Central Intelligence Agency

9 November 2012

Yesterday afternoon, I went to the White House and asked the President to be allowed, for personal reasons, to resign from my position as D/CIA.  After being married for over 37 years, I showed extremely poor judgment by engaging in an extramarital affair.  Such behavior is unacceptable, both as a husband and as the leader of an organization such as ours.  This afternoon, the President graciously accepted my resignation.

As I depart Langley, I want you to know that it has been the greatest of privileges to have served with you, the officers of our Nation's Silent Service, a work force that is truly exceptional in every regard.  Indeed, you did extraordinary work on a host of critical missions during my time as director, and I am deeply grateful to you for that.

Teddy Roosevelt once observed that life's greatest gift is the opportunity to work hard at work worth doing.  I will always treasure my opportunity to have done that with you and I will always regret the circumstances that brought that work with you to an end.

Thank you for your extraordinary service to our country, and best wishes for continued success in the important endeavors that lie ahead for our country and our Agency.

With admiration and appreciation,
David H. Petraeus