Tenants Interest in Purchasing . . claim by Agent?

[David Stott]

Owning a property out of state makes it difficult to source prospective tenants during times of turnover, and therefore, I often employ the use of a RE agent to source tenants. When my current tenants executed a lease, nearly 5 years ago, there was an addendum/amendment added by the agents that essentially said that "in the event lessees purchase the property during the term of the lease, or during any extension of the lease or with 90 days of termination of the lease, the sellers/lessors agree to pay a commission equal to 6% of the sales price" to be split by the two agents.

Of course, my tenants have now expressed interest in purchasing and my question to the BP community is - after 5 years, am I still obligated by this amendment that I signed? I've had no contact with agents since they assisted with this lease over 5 years ago, and therefore, find it hard to believe that they should have a claim . . .

Any advice?