QPR have fined Joey Barton six weeks' wages and stripped him of the club's captaincy over his conduct in their defeat by Manchester City on the final day of the Premier League season.
The club held an internal investigation into Barton's sending off and his actions following his red card.
In a statement, Barton said: "My behaviour was wrong and I accept the punishment imposed upon me."
The Football Association banned Barton, 29, for 12 games over the incident.
Barton was sent off for an off-the ball clash with City striker Carlos Tevez at Etihad Stadium on 13 May but was involved in further clashes with Sergio Aguero and Vincent Kompany before leaving the pitch.
He was found guilty of two counts of violent conduct by the FA and also fined £75,000.
QPR have reached an agreement with Barton that, if he seriously breaches the club's disciplinary procedures again, they reserve the right to terminate his contract.
Barton, who was arrested for affray earlier this month following a night out in Liverpool with his girlfriend, will be absent from QPR's pre-season tour of Asia in July.
The former Manchester City and Newcastle midfielder, who signed a four-year deal with QPR in August 2011 after leaving the Magpies on a free transfer, added on Twitter: "I was reckless and deserved every punishment I received.
"Money comes and goes, it's not important to me. Losing the captaincy and missing 12 games is what really hurts. I was stupid and that what happens when you do dumb things.
"I am confident I'll bounce back."
QPR chief executive Philip Beard said in a statement: "It was important that we took our time to make sure we came to the correct decision, which I believe we have achieved.
"Joey's behaviour, which led to his red card at Manchester City, and his subsequent actions were completely unacceptable and we have made our feelings on this matter known to him.
"I am really pleased with the way in which the club and Joey have worked towards reaching a sensible conclusion and we fully believe he will respond to these sanctions in the correct manner."