You are organizing a business meeting， and you should write to people from other companies and tell them the changes of the meeting (time， location， etc.)。 You will (1) explain why you have to make changes， (2) tell them the changes， and (3) apologize for the changes.
Dear Mr. Smith，
I am writing to inform you about the changes we have made to the high-level meeting between our two companies.
Mr. Anderson， project manager of “Sunshine Cooperation Campaign”， has been ill recently and is currently in hospital for treatment. He is recovering well but won't be able to come back to work until 2 weeks later. As he is the designer and coordinator of this “sunshine campaign”， we feel the meeting could not be held without him.
Therefore， we are rescheduling the meeting to be held one month later， on 9 o'clock， Sunday， 15 July. Also the place of the meeting has been changed from Hilton Hotel to the VIP meeting room at the headquarters of our company， No. 100， Oxford Street. We also might invite senior managers from Greenwell Company to attend the meeting as they have always been an active supporter of this campaign.
We are sorry for any inconvenience that the change of the meeting might have caused you. If you have any questions， please do not hesitate to contact me.
Looking forward to seeing you soon!
Yours sincerely，
Edward Simpson