The company made the announcement late Wednesday, hours after Schnatter apologized for using a racial slur during a conference call in May.
The apology comes after Forbes cited an anonymous source saying the pizza chain's marketing firm broke ties with the company afterward.
Forbes said Schnatter used the N-word during a media training exercise. When asked how he would distance himself from racist groups, Schnatter reportedly complained that Colonel Sanders never faced a backlash for using the word.
In a statement released by Louisville-based Papa John's, Schnatter said reports attributing use of "inappropriate and hurtful" language to him were true.