The Kings said in a statement on Monday that they have "exercised the team's right to terminate the contract of Mike Richards for a material breach of the requirements of his standard player's contract."
The team said it would not comment further.
Richards, who cleared waivers on Monday, had five years left on his contract at a cap hit of US$5.75 million per season.
The Canadiens bought out Parenteau after he cleared waivers.
"I would like to thank the Montreal Canadiens, my teammates and especially the fans for their support while I fulfilled a lifelong dream of playing for my hometown team," Parenteau said in a statement. "I'm looking forward to the next chapter of my hockey career and wish everyone in Montreal the best next season."
Anaheim defenceman Mark Fistric also cleared waivers Monday, while Buffalo forward Cody Hodgson and Nashville forward Viktor Stalberg were placed on unconditional waivers for the purpose of a buyout.