Key legal question
Whether the purchaser of the leased property had to be substituted for the seller in the pending case under Art. 261 CO
Extracted holding
Yes. The purchaser entered the pending proceedings in place of the seller because the case concerned the existence and prolongation of the lease, which continued to affect the tenancy relationship after the transfer.
Extracted reasoning
A transfer of ownership during litigation triggers ex lege substitution where the proceedings concern a continuing tenancy relationship; the cantonal court had to treat the buyer as the proper party.