王轩军

通过什么行为可以订立合同呢？这里所说的“行为”，可分为广义的行为和狭义的行为。我认为，广义的可订立合同的行为可以分为三类，第一是当事人共同签署书面文件，第二是当事人有要约和承诺，第三是除上述两种行为以外的其他行为。而狭义的行为特指上述第三种行为。通过共同签署书面文件和通过要约/承诺订立合同，比较容易理解。但是，在商业实践中，特别是在涉及复杂交易时，合同通常是经过长期谈判达成的，在这一过程中并没有一个可识别的要约和承诺的顺序。这种情况下，若当事人没有共同签署书面合同文件，则很难断定缔约的一致意见是否已经达成以及何时达成。根据国际商事合同通则2016第2.1.1条及注释2和示例1，狭义的订立合同的行为是指，能充分表明达成一致意见的当事人各方的行为。即使不能确定订立的时间，只要当事人的行为足以表明达成一致意见，合同也可成立。

这样说比较抽象，下面的例子应有助于理解狭义的订立合同的行为：A和 B 举行谈判，拟建立一个合资企业从事一种新产品的开发。经过没有任何正式要约/承诺的长期谈判后，在一些次要事项尚待确定的情况下，双方当事人就主要事项达成一致意见（没有签署正式书面文件）并开始履行。随后当双方当事人未能就这些次要事项达成一致意见时，法院或仲裁庭仍可以认定合同成立，因为双方当事人已开始履行合同，以此表明了他们愿受合同约束的意向。

通则第2.1.1条及注释2和示例1的英文原文如下：

ARTICLE 2.1.1
(Manner of formation)
A contract may be concluded either by the acceptance of an offer or by conduct of the parties that is sufficient to show agreement.

COMMENT
2. Conduct sufficient to show agreement
In commercial practice contracts, particularly when related to complex transactions, are often concluded after prolonged negotiations without an identifiable sequence of offer and acceptance. In such cases it may be difficult to determine if and when a contractual agreement has been reached. According to this Article a contract may be held to be concluded even though the moment of its formation cannot be determined, provided that the conduct of the parties is sufficient to show agreement. In order to determine whether there is sufficient evidence of the parties’ intention to be bound by a contract, their conduct has to be interpreted in accordance with the criteria set forth in Article 4.1 et seq.
I l l u s t r a t i o n
1. A and B enter into negotiations with a view to setting up a joint venture for the development of a new product. After prolonged negotiations without any formal offer or acceptance and with some minor points still to be settled, both parties begin to perform. When subsequently the parties fail to reach an agreement on these minor points, a court or arbitral tribunal may decide that a contract was nevertheless concluded since the parties had begun to perform, thereby showing their intention to be bound by a contract.