The defender asked Mainz' club bosses to void his contract which was stipulated until June 2016, reports Xinhua.
"Gonzalo Jara approached us with this request. We understand his private motives and agreed on a cancellation. We thank him for his commitment over the past year and a half," Mainz' sporting director Christian Heidel said on Saturday.
The 30-year-old defender joined the "Nuellfuenfer" from English second division side Nottingham Forest in the summer of 2014 to make 23 appearances since his arrival. Jara is since 2006 part of Chile's national team where he scored three goals in 85 caps.
Eighth-placed Mainz clash with newly-promoted Ingolstadt at the 18th round in Bundesliga on January 23.