Thomas Grilk stepping down as CEO of Boston Athletic Association after Boston Marathon

BOSTON -- Thomas S. Grilk, who has been connected with the Boston Athletic Association for more than 40 years, will step down as the organization's president and chief executive officer after the 2022 Boston Marathon.

Grilk, 74, will be stepping down from his posts on April 30 and making a planned transition into a senior adviser role after more than 11 years leading the nonprofit, the B.A.A., which manages the world's oldest annual marathon, said in a statement.

Chief operating officer Jack Fleming will serve as acting CEO, effective May 1. The B.A.A.'s board of governors will initiate a search for a new CEO.

"It has been an enormous and gratifying privilege to lead the B.A.A. and to serve with a magnificent group of colleagues who have been instrumental in the organization's development and growth," Grilk said in a statement.

B.A.A. board of governors chair Michael O'Leary said Grilk was instrumental in helping the Boston Marathon be included as a founding member of the Abbott World Marathon Majors, which also includes the Tokyo, London, Berlin, Chicago and New York marathons.

Since Grilk became CEO in 2011, the Boston Marathon's official charity program and John Hancock's nonprofit program surpassed the $400 million mark, a growth of more than $300 million during his tenure. According to the B.A.A., the Boston Marathon has generated an estimated economic impact of more than $200 million for the greater Boston economy annually.