Charlesbank is in advanced talks to acquire a stake in the law firm WSHB in a $700mn transaction that would mark one of private equity’s largest forays into the US legal sector.

The planned deal uses a novel financing approach that allows non‑lawyers to acquire a US firm despite professional ethics rules that have historically barred private‑equity ownership in the sector. Charlesbank used a similar approach two years ago to buy the accounting firm Aprio, and the $24bn‑in‑assets group is expanding its professional services portfolio with a stake in Wood Smith Henning & Berman.

WSHB, based in Los Angeles, has more than 550 lawyers specialising in defending companies against product liability, personal injury and other claims. The price was based on a multiple of WSHB’s estimated $46mn of 2026 earnings and set an enterprise value of around $700mn.

The deal would create a management services organisation (MSO) that houses WSHB’s back‑office and other non‑legal operations, allowing private equity to bypass ethics rules while keeping lawyers focused on clients. The MSO structure has been used by private equity to buy medical, dental and accounting practices and is increasingly adopted by personal‑injury firms.