To: XYZ COMPANY

Subject: Regarding Business Collaboration.

Dear Sir/Ma’am

I am ABC, CEO of ABC company. I am writing you this letter for the partnership purpose in our upcoming project. Your company has exceeded In the field of marketing and advertising and we are aware of your work in this field. Our company has been working hard for the last 10 years and has achieved some reputation in the market. Thus we are on the way to reach new limits. 

So it would be a great honor if you would like to work with our company for the upcoming project. We are hoping for a positive reply after which we shall start working on this project together. Thankyou.

Regards,

ABC