Alan Chambers said on Exodus International's website Thursday that the group wants to apologize "to the gay community for years of undue suffering and judgment at the hands of the organization and the church as a whole."
Chambers also says he is sorry the group promoted sexual orientation change efforts and apologized for not challenging Christians who called gays names like "sodomite."
Phone messages left at the group's Orlando, Fla., headquarters were not immediately returned Thursday.
Exodus International was founded 37 years ago. It claimed 260 member ministries around the U.S. and internationally.