Professor Valenduris,

I am grateful to be thought of for such an opportunity; to be viewed by a man of your expertise as even vaguely competent is, indeed, an honour. I intend, however, to return to my studies in September, and I would be loathe to terminate any such contract early. Should you need any assistance in grooming the selected candidate, however, I should be very happy to assist.

Sincerely,