Stephen Blyth has resigned his post as CEO of Harvard Management Company, ending his term less than two years after he took the helm of the investment arm that manages the University’s $37.6 billion endowment.

Blyth, who assumed leadership of HMC in in January 2015, will leave for personal reasons, according to a press release from the University Wednesday, but will remain a senior adviser to the HMC Board. His departure comes just two months after he took a then-temporary medical leave of absence. Paul Andrew, Harvard’s Vice President for Public Affairs and Communication, declined to comment on whether Blyth’s resignation is related to his medical leave of absence.{shortcode-df0d945a3d066d2c8d3d2d9d6aafcc67c1a21e54}

Robert A. Ettl, HMC’s Chief Operating Officer, will continue to serve as interim CEO, and HMC will begin a search to search for someone new to direct Harvard’s investment pool, which helps fund everything from financial aid to House renewal at the University. Harvard has hired David Barrett Partners, an executive recruitment firm, to to lead the search.

Blyth led HMC at a time of concern about the company’s performance and turnover among its leadership. Over the last few years, the returns on Harvard’s endowment have consistently lagged behind several peer institutions, including Yale, MIT, and Princeton. After former HMC head Jane L. Mendillo resigned in 2014, Blyth was tasked with revamping HMC’s performance and restoring its dominance among university investors. Last October, University President Drew G. Faust said she was concerned about HMC’s performance.

“We obviously did not do as well as MIT and Yale and others, and that of course is a concern, and it's very much a concern for Stephen Blyth, who has been making significant changes,” Faust said in an interview at the time.

A professor of the practice of statistics, Blyth may return to teaching, according to statements from Faust and Blyth in the press release.

“Harvard has played such a positive role in my life and, as I look forward to my next chapter, I am delighted to return to teaching and interacting with the students and faculty who remind all of us at HMC why the work that is done here is so important,” Blyth said in the press release.

—Check thecrimson.com for more updates.

—Staff writer Andrew M. Duehren can be reached at andy.duehren@thecrimson.com. Follow him on Twitter @aduehren.

—Staff writer Daphne C. Thompson can be reached at daphne.thompson@thecrimson.com. Follow her on Twitter @daphnectho.