Heidi Gutman/CNBC Josh Harris, one of the cofounders of Apollo Global Management, is stepping down, the firm said Thursday. Harris would remain on the board of directors and executive committee, Apollo said. Leon Block, the Apollo cofounder who was investigated for ties to Jeffrey Epstein, quit the firm in March. Investment firm Apollo Global Management on Thursday announced that cofounder Josh Harris would step down as managing director. He would step down once Apollo merges with its insurance affiliate Athene, the company said in a statement. Apollo's acquisition of Athene, which is set to create a $29 billion conglomerate, is expected to complete in the first quarter of 2022.