Date: __/__/____ (date)
I am __________ (name) and I write this letter on behalf of __________ (company name). I am glad to inform you that we are conducting a conference on __/__/____ (date) and for which we please your kind participation in the conference.
Respected, the motive of the conference is ________ (mention motive) and the same will be conducted at the ____________ (mention venue). We will be more than honoured if you could be present at the venue at the said timings __:__ (time) till __:__ (time).
We expect your quick confirmation and response in this regard. We believe that you would try to spare some time out of your busy schedule.
________ (Contact details)