Jean-Claude Darcheville has been given permission to join French side Valenciennes.
He told the club's official website: "It is a difficult moment for me to leave Rangers, because I played for a year-and-a-half here and I was very happy in Glasgow.
"I had a good relationship with the staff, my manager and the fans - but I need to play football.
"It will be good to go back to France, because I'll be able to see my family there, but I really enjoyed playing for Rangers.
"It was one of the highlights of my career - and last year was my best season, because we won two cups and I scored lots of goals.
"It was a disappointment to lose the SPL in the last game and lose the UEFA Cup final. But I can't forget what happened, because there were still a lot of good memories.
"It has been a special time. I have good friends here who I can call when I leave - and I'll always be a Rangers fan."