Provider - Contractor or Government support organization (or both) providing the process on behalf of the customer.
NIST SP 800-56A
NIST SP 800-95
Provider - The entity (person or organization) that provides an appropriate agent, referred to as the "provider agent" to implement a particular Web service. It will use the provider agent to exchange messages with the requester's requester agent. "Provider" is also used as a shorthand to refer to the provider agent acting on the provider's behalf. ( Web Services Architecture - W3C Working Group Note 11 February 2004, http://www.w3.org/TR/2004/NOTE-ws-arch-20040211)