CNBC co-anchor Simon Hobbs was part of a panel on a show discussing that there are CEOs at top American companies who are gay but have not publicly spoken about their sexual preferences.
Among the panelists was New York Times columnist Jim Stewart who was discussing his upcoming column on oil giant BP's former CEO John Browne.
Browne's book, 'The Glass Closet: Why Coming Out Is Good For Business', details his life as a gay executive who hid his sexual orientation and only revealed it after his retirement.
Stewart, who is openly gay, said he had spoken to many CEOs, whom he knew were gay, but who were not willing to go on record about their experience.
Hobbs intervened saying, "I think Tim Cook is fairly open about the fact that he is gay at the head of Apple, isn't he"
The panel was silenced by Hobbs's remark who then sort to correct himself and said, "Oh dear. Was that an error".
Stewart answered after an awkward silence, shaking his head in disapproval.
"I don't want to comment on anybody who might or might not be," he said.
"I'm not going to out anybody. I called a lot of people and no one at any major company would allow their names to be used."
A report in the Huffington Post said 53-year-old Cook has not been open about his sexuality and has never publicly commented on whether he is gay, an assertion that many media outlets have made since he took over the reins of the technology giant following the death of company founder Steve Jobs.
In a speech last year, Cook had said, "I have seen and have experienced many types of discrimination, and all of them were rooted in the fear of people that were different than the majority".
Cook has publicly advocated for an end to discrimination in the workplace based on sexual identity.
Last year, Cook was named the most powerful LGBT (Lesbian, Gays, Bisexual and Transgender) person on Out magazine's 2013 power list.
He also applauded a recent White House decision to ban gay discrimination at federal contractors.