He has yet to make an appearance in Ligue 1 because his 12-match ban for misconduct during the Hoops' final-day defeat to Manchester City was transferred to the French Football Federation in September.
However, he has made four appearances in the Europa League and is enjoying his time on the South East coast of France.
"I still have a lot of respect for my teammates," he said. "I do not play for money but for my club. If I were the one to decide, I would stay at Marseille."
Barton is under contract at QPR until June 2015.