Grousbeck and the outgoing ownership group Boston Basketball Partners LLC purchased the Celtics for $360 million in 2002. During that group's tenure, the club won NBA titles in 2007-08 and 2023-24 -- the latter representing Boston's league-record 18th championship.

The NBA on Wednesday unanimously approved the sale of the Boston Celtics to a group led by private equity mogul Bill Chisholm, a deal that values the franchise at more than $6.1 billion — the largest ever for an American professional sports team.

This vote had long been viewed as a formality, but it is the last big step before ownership officially changes hands this season. The NBA said in a release that the transaction “is expected to close shortly.