Creo que tú tienes razón al hablar de "prelación", sobre todo a la luz de la siguiente referencia. Por eso estoy sugiriendo esta traducción alternativa, no sé que te parezca.

http://findarticles.com/p/articles/mi_qa5370/is_200707/ai_n2...
An additional drafting technique to reduce any potential ambiguity in this regard is to precede the operative subordination language in the subordination agreement with an applicable "preservation" clause. For example, and with a final parting reference to our earlier hypothetical, a partial subordination of A's claim to C's and D's respective claims should be preceded by a "preservation" clause clearly stating that A is not subordinating any portion of its first-priority position to B, or, stated in the positive, that A is expressly reserving any portion of its first-priority position remaining after C and D are paid.