Bengio, who most recently managed some researchers in the Google Brain team, announced his departure in an email to staff that was obtained by Bloomberg. His last day will be April 28.

Ousted Ethical AI co-leads Timnit Gebru and Margaret Mitchell had reported to Bengio and considered him an ally. In February, Google reorganized the research unit, placing the remaining Ethical AI group members under Marian Croak, cutting Bengio’s responsibilities.

“While I am looking forward to my next challenge, there’s no doubt that leaving this wonderful team is really difficult,” Bengio wrote in the email. He did not refer to Gebru, Mitchell or the disagreements that led to their departures.

In November, Bengio’s then-manager Megan Kacholia met with Gebru to demand she retract a paper co-written with Mitchell and other Google researchers that criticized an AI technology powering some of Google’s search results. In early December, Google dismissed Gebru in what she termed a firing and Google has called an acceptance of her resignation. In February, the company fired Mitchell.

“I learned so much with all of you, in terms of machine learning research of course, but also on how difficult yet important it is to organize a large team of researchers so as to promote long term ambitious research, exploration, rigor, diversity and inclusion,” Bengio wrote in his email.