Here is a sample apology letter for early release from job. You should modify this apology letter according to your need and situation.
I believe that you would have highly disappointed on my early release from job for having worked for such a long time and considered me as a better human resource to match your organizational demands.
I am grateful that you have offered me the best salary package considering my skills and expertise when compared to any other company in this field. The organization being one of the topmost successful organizations in this discipline has done much for its employees in terms of remuneration and support.
I too have the intense sadness of having a release from the company for having worked for such a long period. At the beginning, as a fresher, I was too much interested in joining your organization in order to work in real world projects. But rather giving me intense training sessions, the company recognized my skills and abilities and placed me in real time projects with shorter duration for training.
I believe that you are informed about my wife’s health situation has been evident to you by my recent requests for frequent leave and permissions. She has got some bad disease which causes a periodic fever. I was kept informed the she might be dead if such a condition persists.
Also that it requires medical treatment in a foreign hospital. Since it is a treatment involving several months, I had no choice other than leaving the company in order to take care of my wife’s health.
I complete this letter with the hope that you would understand my situation and accept my sincere apologies for getting an early release from the job unexpectedly without your knowledge.