The fact that you will be leaving our firm shortly has been brought to my attention.  We are very sorry to lose you inasmuch as your work has always been most satisfactory and we were hoping that you would remain with the   [name of firm]   for many years.  I understand that you are leaving for personal reasons that have nothing to do with this organization.

　　I will be happy to provide you with a letter of recommendation， if you so request.  You may find this helpful in securing a position with another firm in your new locale.  Please advise my secretary of your intent in this matter， so that we can have it prepared for you before your departure.

　　I know that I speak for everyone here at   [name of firm] in wishing you the very best of luck in the future.