Executive search firm Heidrick & Struggles International Inc. (NASD: HSII) Chairman Tracy Wolstencroft will step down from his role at year-end, according to a filing this week with the US Securities and Exchange Commission. He will remain a member of the board.

Increased commitments from his new position as president and CEO of the National Geographic Society prompted Wolstencroft’s decision.

The board intends to appoint one of its current directors to serve as chairman in advance of the Heidrick annual shareholders meeting in May 2019. Lyle Logan will continue as lead independent director.

Wolstencroft joined Heidrick & Struggles as president and CEO in 2014, following a 25-year career at Goldman, Sachs & Co. He took a three-month leave of absence in April 2017 for treatment of a benign lung condition, switching to the chairman of the board role upon his return.