Unless you have specifically talked to your listing agent ahead of time and excluded this kind of potential private sale from the requirement to pay commission, the listing agreement typically states that any sale during the term of the contract or holdover period (often 90 days) will entitle the listing agent to commission at the rate stated in the contract. Only a termination of the listing agreement and expiry of the holdover period will allow a private sale to be completed without the payment of commission to the listing agent, If this is a possibility when you list your property with the agent, you should seek an exclusion for this kind of transaction ahead of time.