(1) The owner and the pledgee may agree on a manner of sale of the pledged item that deviates from the provisions of sections 1234 to 1240. If a third party has a right in the pledged item which is extinguished by the alienation, then approval by this third party is required. Approval is to be declared to the person in whose favour it is given; it is irrevocable.
(2) The observation of the provisions of section 1235, section 1237 sentence 1 and section 1240 may not be waived before the right of sale comes into existence.