The heads of SK Group and CJ Group stepped down from their major positions in affiliates, industry sources said Tuesday, in response to the courts' ruling, which found them guilty of corruption. South Korea's No. 3 conglomerate SK Group said its head Chey Tae-won resigned from his position as inside director at key affiliates, namely SK Holdings Co., SK Innovation Co., SK hynix Inc., and SK C&C as of Tuesday.