How can I write a letter of introduction to a company to supply goods and services

Get actual names of the people at the company, and have them addressed personally to them. The envelope should be hand written.

You need to explain why your company can provide what they need and what benefit their company will get.

** as a note 99.9 percent of all introduction letters never get to the actual person making decisions. But are caught and disposed of by lower level staff in larger companies.