With regard to the job you offered, I would like to decline your offer this time. Currently I have a full schedule and also the content of the offer does not match my speciality. I appologize for any convenience this may cause you.
Thank you for your request, but as I have a full schedule now and your request is not exactly in my field, I’m sorry I can not accept it this time.
I strongly regret that I could not accept your offer of the business.
The content of the work is not clearly near with my specialty and I am fairly busy now.
Please do not hesitate to offer me the next job in some occasion.
Thank you very much for your inquiry. We are very sorry but we are now occupied by other works and the item you inquired is not really in the scope of works of our company. Therefore we are obliged to decline your precious inquiry. Your kind understanding would be much appreciated and looking forward to have another opportunity to work for you.