The 6% commission, a standard in home purchase transactions, is no more.

In a sweeping move expected to dramatically reduce the cost of buying and selling a home, the National Association of Realtors announced Friday a settlement with groups of homesellers, agreeing to end landmark antitrust lawsuits by paying $418 million in damages and eliminating rules on commissions.

The NAR, which represents more than 1 million Realtors, also agreed to put in place a set of new rules. One prohibits agents’ compensation from being included on listings placed on local centralized listing portals known as multiple listing services, which critics say led brokers to push more expensive properties on customers. Another ends requirements that brokers subscribe to multiple listing services — many of which are owned by NAR subsidiaries — where homes are given a wide viewing in a local market. Another new rule will require buyers’ brokers to enter into written agreements with their buyers.