Pearson was angered by a question regarding criticism of his relegation-threatened squad this season and called the reporter “an ostrich” before storming out of the press conference after Wednesday's 3-1 defeat.
But speaking at a news conference on Thursday, the 51-year-old Pearson said sorry.
“Apologies,” Pearson said. “They wheel us out and I was not happy about losing.
“I react. Is it pressure? It might be. It's emotion more than anything. I'm not afraid of showing my emotion.
“I also accept when I've stepped out of line so it is only right to apologise.”
Pearson was asked to clarify his views on the “criticism and negativity” after Wednesday's defeat and replied: “If you don't know the answer to that question then I think you are an ostrich.
“Your head must be in the sand. Is your head in the sand? Are you flexible enough to get your head in the sand? My suspicion would be no.”
Pearson has been no stranger to controversy this season and was involved in a touchline spat with a Leicester supporter during a home defeat against Liverpool in December.
Rumours also swirled in February that Pearson had been sacked after a string of poor results and a bizarre sideline tussle with Crystal Palace's James McArthur, where the Leicester boss grabbed the midfielder by the throat.
Seventeenth-placed Leicester remain deep in a relegation battle with 31 points from 34 games, one point ahead of 18th-placed Sunderland but Pearson's side have played a game more.
Leicester had won four straight Premier League matches before the visit of Chelsea and they will be hoping to return to winning ways and condemn Newcastle United to an eighth successive league defeat on Saturday. – Reuters
Original source: Pearson apologises for rant