21st Century Fox General Counsel Gerson Zweifach will leave the company with The Walt Disney Co.’s acquisition, which is expected to close in the first half of next year.

The company said Zweifach will return to Williams & Connolly where he spent more than three decades prior to joining 21CF. He’ll remain with Fox to see the $71.3 billion transaction through to completion.

“Gerson is one of the brightest legal minds in the business and has been instrumental in our growth having successfully led our legal and policy strategies across the globe,” said Co-Chairmen Rupert and Lachlan Murdoch in a statement. “We are grateful for his unwavering leadership during a transformational period for our business. ”

Zweifach has been responsible for global legal operations, including litigation, mergers and acquisitions, ethics and corporate governance matters. He joined the company six years ago from Williams & Connolly, where his litigation practice included media and first amendment cases, as well as patent, anti-trust and securities matters.

“Over the past six and a half years I have benefited from the staunch support of Rupert, Lachlan, James, and our Board, John Nallen and my colleagues who practice law with me here and around the world,” Zweifach said in a statement.