Cravath’s CNN Probe Tests Firm’s Long Alliance With WarnerMedia

Cravath, Swaine & Moore, a Wall Street law firm that has long championed the legal causes of WarnerMedia, faces the delicate task of advancing a probe of its ally’s CNN unit after the departure of its longtime president, Jeff Zucker.

The investigation is in the hands of Cravath partners Katherine Forrest, a former federal district judge in New York, and Benjamin Gruenstein, who has worked with companies on criminal antitrust and insider trading matters, among other engagements.

A person familiar with the inquiry confirmed the two lawyers’ roles. Forrest once represented Time Warner, which later became WarnerMedia, when recording artists ...