Exclusive: CBS, Viacom controlling shareholder to call on companies to merge - sources

National Amusements Inc (NAI), the controlling shareholder of CBS Corp and Viacom Inc , is preparing to call on the two media companies to explore a merger, two people familiar with the matter said on Wednesday.

NAI may contact the two companies as early as this week to ask them to form independent board committees to explore a combination, one of the people said.

The sources asked not to be identified because the deliberations are confidential. Viacom and CBS declined to comment, while NAI did not immediately respond to requests for comment.

(Reporting by Jessica Toonkel and Greg Roumeliotis in New York; Editing by Matthew Lewis)