At least three Am Law 100 firms are advising on a deal that sees Pershing Square Capital Management’s William Ackman unload his roughly 18 percent stake in struggling retail giant J.C. Penney Corp., which has secured investments from rival hedge fund managers.

Ackman’s high-profile boardroom dispute with the management of J.C. Penney last month led him to exit his investment and lose more than $400 million in the Plano, Texas–based company, which has been seeking to modernize its traditional department store operations by branching out into e-commerce.