Barton has not featured in the Rams’ first team so far this season and his future plans are unknown at the moment, although he intends to continue playing.
The 34-year-old told Derby’s official website: "I've thoroughly enjoyed my time at Derby County and leave on amicable terms. I wish the club all the best in the future.
"I am at the stage in my career when I need to be playing first-team football.
"The club and I have agreed that this is the best thing to do both for Derby County and for Warren Barton.
"The management, coaches, staff and fans have always been very kind to me and I'll never forget my time with the Rams."
Meanwhile, another Kevin Keegan signing David Ginola is making the news by putting his name forward for the vacant manager’s job at Spurs – it’s fair to say that the club’s directors won’t be taking the application too seriously though.