GENEVA — The director of the United Nations agency that combats AIDS said Thursday he will step down next year, an announcement that came days after a panel of experts issued a damning review of a leadership style it said had enabled harassment and bullying.

Michel Sidibé, the executive director of the agency, UNAIDS, was due to hold office until January 2020, but he told a meeting of the organization’s governing board in Geneva that he would complete his duties at the end of June.

Mr. Sidibé, a native of Mali, “indicated his wish to have an orderly transition of leadership,” Sophie Barton-Knott, a spokeswoman for the organization, said in an email.

In a report released on Friday, four independent experts called for a change of leadership at the agency, saying Mr. Sidibé had fostered a cult of personality and a patriarchal style of management that “enabled a culture of harassment, including sexual harassment, bullying, and abuse of power.”