Facts
[A.], who died in 1957, left his wife and two daughters [B.] and [C.] as his heirs. Contrary to his last wishes, the heirs concluded a succession agreement on 22/30 July 1958, transferring the real estate property no. 6554 to the widow. To preserve the rights of the co-heirs, the parties agreed that the widow could not sell, bequeath, encumber or modify the property without the consent of the daughters. On 10 September 1985, widow [A.] sold the property to her daughter B. In October 1986, daughter [C.] filed an action to establish the nullity of this sale, on the grounds that it violated the prohibition on alienation provided for in the succession agreement.Considerations
The Federal Tribunal considers that the prohibition on alienation provided for in the succession agreement is lawful in itself. Although this prohibition has only an obligatory effect between the parties, it also applies within the internal relations between the mother and the daughters. Therefore, the sale of the property to daughter [B.] violated this contractual obligation, which renders the sale null and void with respect to all parties.
Although the absolute nullity of the sales contract within the meaning of Art. 20(1) CO is not established, contracts whose content violates provisions of the legal order must be considered null and void. In the present case, the violation of the parties' autonomous rights renders the sales contract ineffective…