139.—(1) A conveyance of the freehold executed in pursuance of the right to buy shall conform with Parts I and II of Schedule 6; a grant of a lease so executed shall conform with Parts I and III of that Schedule; and Part IV of that Schedule has effect in relation to certain charges.
(2) The tenancy held by the qualifying person comes to an end on the grant to him of an estate in fee simple, or of a lease, in pursuance of the provisions of this Part; and if there is a subtenancy section 139 of the Law of Property Act 1925[1925 c. 20.] (effect of extinguishment of reversion) applies as on a merger or surrender.