I deeply regret that I will be unable to keep our appointment scheduled at 12: 00 noon on Wednesday, 7th October 2015. Due to some urgent circumstances in my office, I have to travel to Singapore, hence my inability to attend the aforementioned meeting.
I will return on 12th October 2015 and as soon as I return, I will call your office to reschedule our meeting. Probably we can meet the next day after my return and will call your office in this regard. Once again, I apologies my inability to attend the meeting.
I look forward to meet you soon and collaborate on our joint project.