You are organizing a business meeting, and you should write to people from other companies and tell them the changes of the meeting(times, location, etc.).
1. explain why you have to make changes
2. tell them the changes
3. apologize for the changes
Dear Mr. Smith and Ms. May,
I am writing this letter to inform you the changes we have made to the coming conference between our two companies.
Our supervisor of this project, Mr. Clarkson, is unfortunately not able to get to our headquarters in Beijing from Shanghai in time due to the unexpected flight delay. He has now re-booked his flight and will be get here tomorrow morning. As he is the key person of this project, we feel the meeting could not be held without him.
Therefore, we have to rearrange the meeting to be held tomorrow afternoon, at 15 o’clock. And the location of our meeting will still be Room 123, Continental Hotel, No.100, King Street.
We are very sorry for any inconvenience caused for the changes. If you have any further questions, please do feel free to contact me.
Looking forwards to seeing you soon!