Dear sirmadam:
[organization] would very much like to have someone from your pany speak at our conference on [topic]。
As you may be aware, the mission of our association is to promote 。 Many of our members are interested in the achievements your pany has made in 。
Enclosed is our preliminary schedule for the conference which will be reviewed in weeks。 I'll call you [date] to see who from your pany would be willing to speak to us。 I can assure you that we'll make everything convenient to the speaker。
Sincerely yours,
[name]
[title]