to which it is a party是英文合同中常见的结构，常用在某个协议或者文件的后面作定语，以限定合同主体行使权利和履行义务的范围。

例句一：

Subject to the Legal Reservations, the execution by it of each Finance Document to which it is a party constitutes, and the exercise by it of its rights and performance of its obligations under each such Finance Document will constitute private and commercial acts performed for private and commercial purposes.

受制于法律保留，其签署其作为一方的贷款文件及根据贷款文件行使权利和履行义务将构成出于私人和商业目的的私人和商业行为。

分析：which指each Finance Document,因此这个结构就是it is a party to each Finance Document，其是贷款文件的一方，但是这是一个定语结构，因此就译为“其作为一方的贷款文件”

例句二：

No Group Company, nor any person for whom it is or could be vicariously responsible, has committed any material breach of or failed to perform or observe any material provision of its Charter Documents or of any legislation in any part of the world, or any covenant, agreement, or the terms or conditions of any Permit or any other consent or licence or any judgment or order of a court or competent tribunal or authority by which the relevant Group Company is bound or to which it is a Party or which affects any of its assets.

任何集团公司或者任何集团公司需为其行为负责的任何人均未实质性地违反或者未能履行或遵守其章程文件或世界上任何地区的任何法律的任何重大规定，对相关集团公司具有约束力、相关集团公司作为一方当事人或者影响相关集团公司任何资产的任何契约、协议、或任何许可或其它任何同意或批准的条款或条件、或法院或具有司法管辖权的仲裁庭或当局所发出的任何判决或命令。