Attorneys from three Am Law 100 firms have scored lead roles on the proposed sale of the National Basketball Association's Atlanta Hawks to private equity titan Antony Ressler, including Ressler's sister-in-law, Sullivan & Cromwell corporate partner Alison Ressler.

News of the deal, which emerged late Wednesday and was covered by sibling publication the Daily Report in Atlanta, comes roughly six months after the Hawks' ownership retained DLA Piper to manage an auction of the franchise. Over the past few months, the Hawks were valued at up to $1 billion, thanks to a surge in valuations for professional sports teams, which has led to key advisory roles for corporate lawyers at a few select Am Law 100 firms.

DLA Piper is advising Atlanta Spirit LLC—the team's seven-member ownership group—on their sale of the Hawks, while Proskauer Rose is representing the NBA on due diligence matters.