Dear Mr. Johnson,
I am writing you to ask if you would be willing to provide me with a job reference.
I am currently in the process of relocating and, as such, am searching for a new source of employment. Given the impressive history and status of Widgets, Inc., a reference from you would greatly enhance my portfolio. I entered your company immediately out of college, and in the twelve years that followed, my experience there molded me into a hard worker with a positive track record and notable list of contributions. If you are able and willing to attest to my record with your company, would you also be willing to provide me with a reference?
If you need any additional information, I would be glad to provide you with my current resume and a list of the work-related skills I possess. My supervisor is Ms. Lydia Smith, and she would also be able to provide you with further information about my history with your company.
Thank you for your consideration, and thank you for any help you can provide me.
Sincerely,
John Doe