Recently I got an offer letter from one of the top companies. However, because of some unexpected situations I want to reject the offer. In the mail I've explained all the reasons, but I am finding it difficult to find a sentence for the end of the mail. Should I say "I apologize for the inconvenience" or "Sorry to inform you that I am rejecting the offer"
Would usage of 'reject' be rude? Could someone suggest an exact sentence or a set of sentences? Thank you.