I saw a listing in the MLS that offered compensation for cooperating brokers of that MLS. The listing broker wrote in the agent remarks that the compensation offered would be reduced if the contract closed after a certain date. Does this violate MLS rules?
Yes. MLS policy and rules require that a listing broker specify on each listing what compensation is offered to other MLS participants for their services in the sale of that listing. Such offers must be unconditional except that entitlement to compensation is determined by the cooperating broker’s performance as the procuring cause of the sale. The offer you described appears to be conditional and therefore prohibited by the MLS policy and rules.
Please note that this does not prevent the listing broker from offering compensation other than the compensation indicated in the MLS, provided the listing broker informs the other broker in writing in advance of submitting an offer to purchase.