Hello - I found the following article on the DOS site. It looks like a written commission agreement is not required in order for a broker to earn his fees. "Without a written commission agreement, the commission is earned when the broker has obtained oral agreement between the landlord and tenant on the essential terms of the tenancy, even if the tenant never takes occupancy or signs a lease." Please advise.
http://www.dos.ny.gov/cnsl/apthunt.html