1. A member of a grouping may withdraw in accordance with the conditions laid down in the contract for the formation of a grouping or, in the absence of such conditions, with the unanimous agreement of the other members.

Any member of a grouping may, in addition, withdraw on just and proper grounds.

2. Any member of a grouping may be expelled for the reasons listed in the contract for the formation of the grouping and, in any case, if he seriously fails in his obligations or if he causes or threatens to cause serious disruption in the operation of the grouping.

Such expulsion may occur only by the decision of a court to which joint application has been made by a majority of the other members, unless otherwise provided by the contract for the formation of a grouping.