Any change, as a result of the introduction of the euro, in the composition or definition of a variable rate or an index referred to in an agreement shall have no effect on the application of that agreement.
When this variable rate or index disappears as a result of the introduction of the euro, the Minister responsible for the economy may designate, by decree, the variable rate or index which replaces it.
However, the parties to the agreement may derogate, by mutual agreement, from the application of the rate or index thus designated.