AT&T is believed to be evaluating whether to sell the headquarters in Manhattan, New York, that it has owned for more than 80 years.
The telecommunications giant confirmed that it had been speaking to estate agents about the property over the past few weeks, and the rumoured transaction could bring it in up to $150 million.
The company is expected to lease back between 30-40 per cent of the office space from any potential buyer.
Tesla founder leaves OpenAI group - while Valve Software's Gabe Newell joins
'If someone were to venture into one of these relatively benign black holes, they could survive, but their past would be obliterated,' he claims
Captured by accident by an amateur astronomer in Argentina
Electric eel the inspiration for battery that uses hydrogel to store power