With Nathan's regular position in the centre becoming an extremely competitive spot this season, the two parties have agreed his release from the club.
He said: "I'm sorry to be leaving before the end of the season. I've enjoyed my time in Glasgow and I wish the Warriors squad all the best with the current campaign and beyond. I haven't found another club yet, but I've never been fitter and I'm optimistic about the future."
Head coach Gregor Townsend said: "Given the strength and depth that we now have in our midfield, Troy's opportunities this season have been limited.
"With that in mind, both parties have agreed that it would be in Troy's best interests to move on so that he can focus on securing his future at another club. We thank Troy for his contribution to Glasgow Warriors and wish him continued success in his future career."
Since joining Glasgow Warriors in the summer of 2011, Nathan has had 17 RaboDirect PRO12 appearances, four Heineken Cup appearances and scored two tries.
Meanwhile, German Araoz has completed his contract with the Warriors having spent almost three months at the club.
Townsend continued: "We'd like to thank German for coming to Glasgow at a time when a number of our props were injured.
"Though it is great to see Ed Kalman and Jon Welsh now return to fitness, German has been extremely valuable to us on and off the pitch.
"We wish him all the best with his future career."