The NBA officially has signed off on the sale of the Boston Celtics to Bill Chisholm and his partners.

The league announced Wednesday that its Board of Governors "unanimously approved the sale of the controlling interests in the Boston Celtics to an investor group led by Bill Chisholm."

"The transaction is expected to close shortly," an NBA spokesperson said in a statement.

The approval came one day after ESPN reported that Chisholm -- whose group bought the Celtics for $6.1 billion -- would immediately take over as team governor upon completion of the sale.

When Chisholm's record offer was accepted in March, the team said current Celtics governor Wyc Grousbeck would remain in that role through the 2027-28 season. Instead, Grousbeck will serve as CEO and alternate governor under Chisholm.

The change in leadership structure reportedly was made because Grousbeck's ownership stake will be "slightly less" than the 15% the NBA requires team governors to hold.

Chisholm and Grousbeck "plan to run the team together as originally planned," ESPN's Ramona Shelburne reported, with president of basketball operations Brad Stevens and team president Rich Gotham "continuing to run basketball and business operations," respectively.

The Celtics' new ownership group also includes current Celtics minority owner Robert Hale, Related Companies president Bruce A. Beal, Jr., and private equity firm Sixth Street Partners and Indian steel CEO Aditya Mittal.