The move marks a reset in relations between Elon Musk's social media platform and the advertising trade body.
The announcement follows a March ruling in which a U.S. judge dismissed X's antitrust lawsuit accusing the WFA and major companies, including Mars, CVS Health (CVS.N) and Colgate-Palmolive (CL.N) of orchestrating an illegal boycott of the platform.
U.S. District Judge Jane Boyle in Dallas said X had failed to show it suffered harm under federal antitrust law.
X, formerly known as Twitter, filed the lawsuit in 2024, alleging the advertisers, acting through WFA's GARM initiative, collectively withheld billions of dollars in advertising spending from the platform due to disagreements over content moderation policies.
In a joint statement on Wednesday, the WFA reaffirmed its commitment to freedom of speech, saying the principle has been part of its constitution since 1953 and is shared with X.
The trade body also said it had permanently discontinued GARM in August 2024 and would not revive the initiative or create a similar program.
GARM was launched by the WFA in 2019 to develop common standards aimed at preventing advertisements from appearing alongside harmful online content.
The two organizations said they also agreed that brands, platforms and consumers all stand to benefit from continued innovation in brand safety.
