Kernrechtsfrage
Which party was entitled to terminate the sublease after the transfer of the main lease?
Extrahierter Entscheid
X. SA, as the new main tenant and effective sub-lessor, could validly terminate the sublease; Y. AG had already lost the right of use and its notice had no legal effect.
Extrahierte Begründung
A valid transfer of the main lease under Art. 263 CO substituted X. SA for Y. AG in the lease relationship. Once Y. AG had lost the right of use, it could no longer sublet or terminate the sublease. The sub-tenants' continued occupation and payment of rent, together with X. SA's conduct, showed a new sublease relationship with X. SA.