Black Rock, the modernist skyscraper designed by Eero Saarinen that has been CBS headquarters for more than half a century and symbolized the network’s invincibility, is being considered for a sale.

The 36-story tower, clad in light-erasing black granite at 51 West 52nd Street in Manhattan, could be sold as part of a larger review of the company’s real estate holdings, Robert M. Bakish, the chief executive of ViacomCBS, announced Monday at an investor conference. The company has hired the real estate investment firm CBRE Group to evaluate the entire roster of buildings, offices and studios.

“We believe that is a very material financial asset,” Mr. Bakish said of Black Rock at the conference, which was put on by UBS. “We also believe it is not an asset we need to own and, in fact, that value can be put to better use elsewhere.” The additional cash could be used to buy back more stock, an artificial way to raise the value of shares.

CBS merged with its sibling company, Viacom, last week in a $25 billion deal that united the country’s largest television network with the Paramount film studios and a clutch of cable channels that include MTV and Comedy Central. The newly combined entity anticipates $500 million in cost savings, largely from job cuts, but they could also come from the sales of properties in New York and Los Angeles.