in an exclusive-agency listing, only 1 broker has the right to represent the seller, but the seller has the right to sell his property without the broker and without paying a commission. the listing agreement may have a multiple listing clause, which allows the broker to list the property on the multiple listing service (mls), which is both an association of brokers and a database of real estate properties provided by the brokers participating in the multiple listing service. automatic extension clauses create a contract with no real expiration date, and are not in the seller’s best interest, since the broker is not motivated to sell the property within a reasonable time.