Simply replace the unfilled areas such as "" and "[date]" with your information.
Our team has been thoroughly reviewing your counter proposal of [date] for the [project name] project. After much deliberation, we have decided that we must decline this offer. Your counter proposal does not meet our needs in this venture, nor does it offer us fair terms. We ask that you please reconsider our original proposal of [date].
We understand that this is an important project for your organization. This is a great opportunity for us to form a business alliance that will benefit both of our company's. Our original proposal has been designed to provide you with a business solution at a fair and reasonable price.
Please let us know how we might best reach an agreement.