[These are Sample letter to reject or regret accepting work offered by a candidate. You can also follow these formats as a Letter to reject a business offer. You can modify these formats as your requirement.]
Date…
Authority name…
Organization/Institute name…
Address…
Sub: Letter to Reject Work Offer
Respected (name),
Extremely sorry for not getting back to you was really busy in the last days also I think the thesis is not my area of interest I was taking it as a proposal initially but I guess it’s not. (state your actual problem and situation). Actually, I have experience of writing professional proposal and reports as having worked in a development consultancy for more than one/two years as an associate economist so my interest is something of that kind I am finding this thesis thing a bit different and I guess as for now, its time would be over too. If you got anything you think I could do please tell me I would look forward to it.
Thanks for your anticipation,
Your name…
Contact no. and Signature…