German to English Tech/Engineering Law: Contract(s)

this word has been causing me a bit of difficulty. It appears in a document that deals with the handling of claims.

Context:
Als Vertragspartner gelten Kunden, Konsortialpartner, Rahmenvertragslieferanten und Lieferanten.

can anybody give me a good translation of this? I have been thinking about "general contract supplier" but that sounds a bit flimsy somehow, "general contractor" sounds good but I think that's wrong and "provider of services within the scope of a general agreement" which is perhaps a bit long-winded.

Many thanks for your help in advance