What are ‘reasonable endeavours’?

Rhodia International Holdings Ltd and another v Huntsman International LLC QBD TLR 6 April

The defendant entered into a contract with the claimants, under which the defendant was to use reasonable endeavours to obtain the consent of a third party to the novation of a contract. There appears to be some division of judicial opinion as to whether ‘reasonable endeavours’ is to be equated with ‘best endeavours’. As a matter of language, in business common sense, untrammelled by authority, one would surely conclude that they did not mean the same thing. That was because there might be a number of reasonable courses which could be taken in a given situation to achieve a particular aim. An obligation to use reasonable endeavours to achieve the aim probably required a party to take any one reasonable course, not all of them, whereas an obligation to use best endeavours probably required a party to take all the reasonable courses he could.