Corporations: Joint Tenancy
It would appear that a corporation can not hold title as a joint tenant with an individual. This would seem so because a corporation has perpetual succession, while a natural person's title would devolve to his heirs or devisees, making the two interests essentially different, thus preventing them from satisfying the Unity of Interest, one of the four unities necessary in order to create a joint tenancy. (It is for a similar reason that I would surmise that spouses as tenants by the entirety could not create a valid joint tenancy with a third individually: the tenancy by the entirety, though concerning natural persons, has been described as an "entity," with respect to which a third party could not hold as joint tenant.)
It is unlikely that one corporation could take title as a joint tenant with another corporation. Although the interests would not disparate as in the example above, with perpetual succession and existence being the nature of corporations, the survivorship feature of a joint tenancy, an important feature indeed, becomes but an illusion.
There are statutes that make provision for corporations to take title as joint tenants, but it would seem that without the benefit of these statutes such a tenancy could not exist in connection with these corporate entities.
1 I am aware that Ontario Canada has some. R.S.O. 1990, c. C.34, §§43(1), 43(2).