Dear

We have assigned     [name of rep]    as our new
representative for your area.     [name of rep]
has been with our firm for quite some time and is
extremely experienced in all aspects of our production.

[name of rep]     will be coming to  [name of city]
on     [date]     and will be calling on you in the
morning if that doesn't conflict with your schedule.
If there is any problem with that date, please let us
know.