This letter is from your business to another business suggesting that you work together to reach goals. It should offer teamwork, not dominance by one company or the other.
1234, Main Street
Boston, MA 02123
<Recipient Address Goes Here>
It seems clear that Abc Company and <other company name> share many of the same goals. And since two companies working together are immeasurably stronger than two companies competing, I'd like to propose a strategic alliance.
I would like to meet with you to discuss combining our efforts to <describe alliance action>. I think that by working together, we could increase market share for both companies and build a very profitable long-term relationship.
If you're interested in the possibilities, please give me a call at <phone number> as soon as possible. We can arrange a time to sit down and set up what could be a very profitable, enjoyable alliance. I look forward to hearing from you.
encl: <List of enclosed items goes here>