By Chibuike Oguh

(Reuters] – Apollo Global Management (NYSE ) stated Monday that Roger Ferguson, the former CEO of TIAA, was no longer able to join the company after announcing his appointment.

Apollo had made the announcement in October about Ferguson’s arrival, six months after he resigned as asset manager Teachers Insurance and Annuity Association of America.

Apollo, however, stated that Ferguson will not accept the new position. “Roger informed us recently that he had ongoing commitments with the previous employer which are prohibiting him from working for us at this moment. Apollo’s spokesperson for the company said that Roger is highly respected and that they wish him well.

Ferguson did not respond immediately to inquiries for comment.

Apollo’s reversal comes after it has made high-profile hirings to strengthen its corporate governance following the departure of Leon Black, co-founder and ex-chief executive. This was in response to an investigation into his connections to Jeffrey Epstein (a financier and convicted sexual-offender). Jay Clayton, who was the former Chairman of Securities and Exchange Commission in March, was named by Apollo.

Ferguson (70) was the Federal Reserve vice chair between 1999-2006, before joining TIAA. Ferguson sits on several boards, both corporate and non-profit.