Invitation to talk by a distinguished speaker / expert.
We have invited [Speaker / Host] to [speak / host] a [talk / conference] on [topic] to be hosted by on [date] at [time]. [Speaker / Host] is very distinguished in the area of [field] and has [number] years of experiences in [specific area of specialisation]. [He / She] is also a [Other Distinguishing Titles – e.g. professor of university, fellow at institute, chairman of society, member of the parliament etc.].