How to write a letter introducing a new department in the company in order to obtain the help of coworkers to market this new department to their current and new client database?`

Why not just write a letter saying what this department will do in general terms and why it was created and ask workers to come back with thoughts on how they could use the services of this department to improve what they are doing. It's hard to suggest anything specific as we have no idea what the company does and what the new department is.

How Do You Introduce A Service Industry To A Major Companies To Give Dealership Rights.