FILE — Robert A. Brown speaks with reporters in his office on the campus of Boston University, Tuesday, April 25, 2006, in Boston, several days before being formally inaugurated as the school's president during ceremonies at the university. Brown said Wednesday, Sept. 7, 2022, he will step down at the end of the current academic year, bringing to an end an 18-year tenure during which the school gained membership into the prestigious Association of American Universities, grew its endowment more than fourfold, and developed new interdisciplinary programs. (AP Photo/Steven Senne, File)

BOSTON (AP) — Boston University president Robert A. Brown said Wednesday he will step down at the end of the current academic year, bringing to an end an 18-year tenure during which the school gained membership into the prestigious Association of American Universities, grew its endowment more than fourfold, and developed new interdisciplinary programs.

“My longevity in the position and the natural rhythms of the university have led me to the conclusion that it is time for me to step aside and for new leadership to take the helm,” Brown said in a letter to the campus community.

He plans to take a sabbatical, then return to teaching in the university’s engineering college.

While BU joined the AAU, an organization of the top research universities in the U.S. and Canada, and the endowment grew from about $700 million to $3 billion, Brown said he is most proud of making the private school more affordable and diverse.

“Of all our accomplishments, I am most proud of our large commitment to undergraduate student need-based financial aid and its impact on the diversity of our student body,” he wrote.

The school has about 36,000 students and the cost of undergraduate attendance this academic year is almost $83,000, according to the school’s website. It traces its roots to 1839 and moved to Boston in 1867.

Brown, 71, is a native of San Antonio, Texas, who has an undergraduate degree in chemical engineering from the University of Texas and a PhD in chemical engineering from the University of Minnesota. He became BU’s 10th president in 2005.

The leaders of several other high profile New England universities, including Harvard, Dartmouth and the Massachusetts Institute of Technology have this year announced plans to step down.