April 27 (Reuters) - Natixis SA:
* François Riahi appointed CEO of Natixis, the investment bank said.
* Riahi to succeed Laurent Mignon.
* Riahi’s new role will become effective on June 1, 2018.
* Francois Perol, the head of France’s second-biggest banking group BPCE, will step down in June and be replaced by Natixis chief Laurent Mignon, BPCE said earlier on Thursday.
* Further company coverage: (Reporting by Ingrid Melander)