Barton spent the 2012-13 season on loan with Ligue 1 side before returning to England but admits he would relish the opportunity to join the Marseille staff once again.
The Merseyside-born playmaker made 25 appearances during a season-long loan at the Stade Velodrome, registering numerous assists as the club sealed Champions League qualification as runners-up in Ligue 1.
Despite enjoying his time at the club, the Englishman believes he fell out of favour following his loan spell as Marseille brought in several new signings.
"I have not lost hope to come back to l'OM one day," Barton told French radio station RMC. "I felt l'OM really wanted me for my first season and I didn't have the same feeling then.
"I didn't feel such desire. Marseille had other priorities with Dimitri Payet, Florian Thauvin or Giannelli Imbula.
"What happened last summer? It was a difficult situation. I was still under contract with QPR, it was a financial matter."
Despite featuring in 12 of QPR's 13 Sky Bet Championship games since returning to his parent club, Barton harbours regrets after leaving France.
"If I had joined l'OM, the difference would have been huge, about €2.5 million," he added.
"It is difficult for a player to accept such a wages decrease when you don't feel you are a priority.
"I have some regrets. I love l'OM, the city and the fans. Why not come back on the staff?"