Pardew's comments included a particularly offensive four-letter word.
Alan Pardew: "I hear that it's been picked up a little bit, and I apologise for my comments 100 per cent.
"It was a heat of the moment thing.
"We just had words that we always have as managers, to a degree. I have apologised to him and fortunately for myself, he has accepted that.
"No, I don't think it merited that word, if I am honest.
"As I said, I have apologised for that particular word, but we sort of tease each other a little bit and have words."
Pellegrini insisted he did not know what Pardew had said to him, but was untroubled by the exchange, although he did accuse the Newcastle boss of questioning every decision the officials made.
He said: "I'm not surprised because I think it is impossible to complain about every decision of the referee during the match.
"I know they were playing at home and they have an advantage in that sense, but it's impossible for the referee if you are complaining at every decision.
"That was my only problem with Alan, but nothing important."