From the NJ Real Estate Commission we get this...
"Pursuant to N.J.S.A. 45:15-1 and 45:15-3, if a person or firm rents, or offers or attempts to negotiate the rental of real estate, or collects or offers or attempts to collect rent for the use of real estate, or assists or directs in the procuring of prospects or the negotiation of any transaction which does or is contemplated to result in the leasing or renting of any real estate, they must be licensed as a real estate broker if they do so for a fee, commission, or other valuable consideration, or by reason of a promise or expectation of such compensation. Thus, when property management firms provide any of these services for compensation, the statutory requirement for licensure as a broker does apply to them."
This info came from:
Official Publication of the NJ Real Estate Commission
Department of Banking and Insurance
20 West State Street, CN 328, Trenton, NJ 08625-0328
The link to this is http://www.njstatelib.org/digit/905/r287/Spring1997.htm
Keller Williams Atlantic Shore
Although I m not an attorney and you should direct this question to an attorney... I am thinking any designated party authorized by the landlord. -or- if the landlord died, the executor of the property / attorney / heirs. I am curious, why the question?