ChD 19 February 1998. B was surety for Alpine Computer Services (A), the tenant. In 1991 the landlord (C) accepted rent from GA, who had sought consent to an assignment of the lease, on the basis that it was paid on behalf of A. Further rent was accepted from GA during 1992. C regarded A and GA as sister companies under the same control, and the occupation by GA as under some form of informal licence. A went into creditors` compulsory liquidaton and the liquidator disclaimed the lease in June 1996. A statutory demand for arrears of rent was made on B, and B`s application to set it aside was dismissed by the registrar. B appealed contending there had been an implied surrender by A and an acceptance of GA as the new tenant. "Held" there was no evidence that there was an offer by A to surrender, no evidence that GA took possession on this basis with the consent of C, and C had not failed to mitigate his losses by failing to take possession of the premises. Appeal dismissed.