Dear Manager,
After a serious consideration, I have definitely decided to resign from the department effectively on September 28th. I think you will readily understand my decision in view of my personal financial problems. I feel that great opportunities would be available to me to cope with these problems in some other companies.
The two years working with you and my colleagues have been very pleasant and have provided a great challenge. I enjoyed working with you. and I regret very much the necessity of leaving the department only because of my extreme economic pressure.
Before my leaving. I will certainly help in training the person you select to fill my position. If at any future time a problem should arise, I shall be happy to assist in any way I can.
Yours sincerely,
×××
Why does he resign from the department
Because of（）.