CBS occupies less than half of the building now; only 15 of its 38 floors. Other tenants include Cushman and Wakefield and law firm Wachtel, Lipton, Rosen & Katz. C&W declined to speculate on the report. If CBS retains its space, the price is expected to come down significantly. ABC and NBC, which were also bought during the last few years, have moved some of their operations out of the Midtown area. CBS has been moving personnel to other locations since 1987.

This is not the first time Black Rock has been offered for sale. Last year when buyers were being sought, the offers, said to be in the neighborhood of $300 million, were considered too low and it was taken off the market.

Designed by Eero Saarinen, the 36-year old building was accorded landmark status in 1997, just three years after it was eligible for the designation.