Celtics alternate governor Aditya Mittal and minority owner and CEO Wyc Grousbeck are making a bid to purchase the NFL’s Seahawks, league sources confirmed Thursday.

The sources said if the group secures the winning bid for the Super Bowl champions, Mittal would be positioned to become the controlling owner, holding at minimum the 30 percent stake required by the NFL. Grousbeck would assume a smaller share. Sources said the roles Mittal and Grousbeck hold with the Celtics would remain unchanged, and both remain committed to the franchise.

Mittal is the CEO of the global steel giant ArcelorMittal and a member of one of India’s richest families. Last year, he committed $1 billion to Bill Chisholm’s investment group that purchased the team from the Grousbeck family at an initial valuation of $6.1 billion. Wyc Grousbeck maintained a 13 percent stake in the Celtics, and that figure is expected to fall to about 3 percent when the final phase of the deal closes in 2028.

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Mittal is based in London and Grousbeck lives in Boston, where he remains a visible presence courtside at most Celtics games. A source said that if their bid for the Seahawks is successful, both also will have part-time residences in the Seattle area.

When the Celtics went up for sale last year, Mittal initially explored a bid to become the lead governor. He then chose to back Chisholm with a $100 million pledge that swelled to 10 times that figure as he became increasingly enamored with the franchise.

A source said Chisholm has given Mittal and Grousbeck permission to pursue ownership of the Seahawks. The source said Mittal and Grousbeck grew close while working together in the fundraising process to finalize the Celtics bid, and now they appear prepared to enter a new high-stakes venture together.

It has become common for owners to hold stakes in NBA and NFL teams simultaneously.

Josh Harris is the managing partner of the 76ers and Commanders, Gayle Benson owns the Pelicans and Saints, Stan Kroenke owns the Nuggets and Rams, and Jimmy and Dee Haslam are part of the Bucks’ ownership group and managing partners of the Browns.

According to Sportico, billionaire venture capitalist Vinod Khosla, who already has a minority NFL ownership stake in the 49ers, also is preparing a bid for the Seahawks. Sportico said the Seahawks are valued at $6.59 billion, but the final price tag is expected to be considerably higher.

The Seahawks are for sale from the estate of former Microsoft co-founder Paul Allen, who died in 2018. A directive in Allen’s will called for the eventual sale of the Seahawks and Trail Blazers, which he also owned, with proceeds going to charity. Portland’s NBA franchise was sold to a group led by Tom Dundon, who also owns the NHL’s Hurricanes, for a reported $4.25 billion.

Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him @adamhimmelsbach.