[DATE, ex. Wednesday, June 11, 1998] 

[NAME, COMPANY AND ADDRESS, ex.
John Smith
XYZ Inc.
1234 First Street
Suite 567
Anycity, Anystate  85245] 

Dear [NAME, ex. John Smith],

It has been a pleasure to serve you in the past, and we look forward to doing business with you in the future. 

I am writing to you regarding a change in our administrative arrangements.  [MENTION RATIONAL BEHIND CHANGE AND HOW IT MAY, IF AT ALL, BENEFIT CUSTOMER, ex. To provide you with better technical assistance, we have undergone a change in administration whereby sales and support staff now operate independently.  As always, Joseph Johnson will be pleased to fulfill your sales orders.  If you require any technical assistance, however, we now have a dedicated and highly-skilled technical assistance staff available to serve you.  Allow me to introduce Mr. John Porter, who will handle all your technical inquiries.  You may reach him directly at XXX-XXXX.

Indeed, we will continue to serve you to the best of our abilities.  You can always call me at XXX-XXXX if I may be of any service to you. 

Sincerely,

[YOUR NAME, ex. Jill Jones]