Dear :

I'm pleased to notify you that your request for a [amount of money] credit line has been approved. Please sign the enclosed agreement and return it to me. As soon as I have received the agreement, you may begin ordering against your credit account.

On behalf of [company], let me welcome you to our select group of credit buyers. We look forward to a mutually profitable business relationship.

Sincerely yours,

[name]

[title]