“(6) (a) Nothing in section 55 or 55A of this Act shall prevent the parties to a contract for the international sale of goods from negativing or varying any right, duty or liability which would otherwise arise by implication of law under sections 12 to 15 of this Act.

(b) In this subsection ‘contract for the international sale of goods’ means a contract of sale of goods made by parties whose places of business (or, if they have none, habitual residences) are in the territories of different States and in the case of which one of the following conditions is satisfied:

(i) the contract involves the sale of goods which are at the time of the conclusion of the contract in the course of carriage or will be carried from the territory of one State to the territory of another; or

(ii) the acts constituting the offer and acceptance have been effected in the territories of different States; or

(iii) delivery of the goods is to be made in the territory of a State other than that within whose territory the acts constituting the offer and the acceptance have been effected.”.