Keith Taggart, president of the association, declined to comment and referred questions to the group's attorney, Richard Ogden.
Ogden said the association will ask for the lawsuit to be dismissed.
“The Oklahoma City Metropolitan Association of Realtors ... feels the claims in the lawsuit are without merit and will vigorously defend the matter. Because this is a personnel matter, (the association's) comments should be reserved for the litigation or arbitration as would be appropriate.”
Johnson has worked with Realtors groups for a decade, most recently as CEO of Quad City Area Realtor Association in Bettendorf, Iowa.
Before that, he was CEO of St. Charles, Mo., Association of Realtors near St. Louis. Previously, he was deputy chief of staff for then U.S. Rep. Jim Nussle, R-Iowa.