It is with mixed emotion yet firm conviction that I write this Letter of Resignation from my current Assignment at XYZ Company in Cheshire, Connecticut.
My contract over the last X months with this excellent company and its many fine people has been a significant part of my professional and personal life. Please understand that I have made my decision after considerable deliberation, and only because an outstanding opportunity presented itself to significantly further my career and help me achieve my own goals.
I am therefore resigning from my position at XYZ Company effective June 15th, 20XX. This will allow sufficient time to complete current commitments prior to commencing with my new employer on June 18th, 2007.
I hope that you will understand and accept my decision, and that I will have your support in making this change as easy as possible for the staff and department.