Celtics reportedly have another co-owner in place

Aditya Mittal, CEO of global steel giant ArcelorMittal, is expected to join the Celtics as alternate governor.

Bill Chisholm (fifth from left) has a sizable group of investors as part of his Celtics ownership group. (Danielle Parhizkaran/Globe Staff)

By Conor Ryan

May 22, 2025 | 7:30 PM

1 minute to read

Bill Chisholm is set to be the largest stakeholder in the Boston Celtics when the franchise’s $6.1 billion sale to him and his ownership group is finally approved by the NBA’s Board of Governors.

But, more details are starting to emerge about the other key figures who helped facilitate the sale of the Celtics to Chisholm’s group.

According to The Boston Globe’s Adam Himmelsbach, Aditya Mittal, CEO of global steel giant ArcelorMittal, is expected to join the Celtics as alternate governor following a $1 billion investment as part of Chisholm’s ownership group.

A source familiar with the transaction told Himmelsbach that Mittal is expected to eventually become the second-largest stakeholder after Chisholm. Private equity firm Sixth Street, which will be a silent partner, will hold the third-largest stake, according to the source.

When Chisholm’s ownership group was announced as having the winning bid in March, the deal had not been fully financed — with Himmelsbach’s source stating that Mittal was recruited by Chisholm and current lead governor Wyc Grousbeck to help bridge the gap and close the sale.

“Aditya has long been a huge supporter of the Boston Celtics, and when Wyc and Bill approached Aditya he saw it as a tremendous opportunity to get involved with this incredible team,” a spokesperson for Mittal said in an emailed statement to Himmelsbach. “Obviously, he remains super focused on ArcelorMittal and also very much looks forward to supporting the team further.”

Mittal is the son of Lakshmi Mittal, who founded Mittal Steel Company and remains as executive chairman of ArcelorMittal. ArcelorMittal is the second-largest steelmaking company in the world.

Once the sale of the Celtics is officially approved by the NBA’s Board of Governors, likely later this summer, Chisholm’s group will purchase 51 percent of the team at that time. Grousbeck will remain on as lead governor until the balance closes after the 2027-28 season.