Sir Trevor McDonald said he turned down a BBC job before he became a big name after he was told the broadcaster needed "more black reporters".
The former ITV newscaster, 80, said he was approached by the corporation "very, very early in my career".
He told The Jonathan Ross show: "I got a call from somebody at the BBC saying, 'Could you come over? I'd like to interview you.'
"There was a lot of white wine and smoked salmon sandwiches and I thought all my ships were coming in at once.
"I thought getting a call from BBC TV meant that he had heard that I had done some TV in the West Indies."
But the person he was speaking to told him, "'You know, we'd really like to have you because we have come under pressure by the Race Relations Board (established by the Race Relations Act in 1965) to hire more black reporters,'" Sir Trevor said.
"The smoked salmon suddenly stuck in my throat and the white wine tasted not as nice as it had done before," Sir Trevor, who retired from ITV's News At Ten in 2008, added.
He said: "I have only small philosophical problems with this idea of positive discrimination.
"But I did not want to be employed solely because I was black.
"I wanted to be employed on merit.
"So I thought he had heard about my reputation in Trinidad as a television newsreader and he then disclosed that he'd never heard Trinidad and Tobago television in any way, shape or form.
"So I made my excuses and left. I turned down the job."
Peter Crouch also appears on the ITV show (Nick Potts/PA)The broadcaster said that he recognised the need for positive discrimination in countries like South Africa
Supermodel Jourdan Dunn, ex-footballer Peter Crouch and comedian and actress Aisling Bea also joined the show.
Bea spoke of being superstitious, saying: "I have crystals in my bra right now, just in case... It's a daily thing I suppose, it's like what if they work?
"I'd always put them in my bra for a gig to make sure the gig would go well, rather than relying on work and craft!"
The Jonathan Ross Show airs on Saturday at 10.20pm on ITV.