The Bosnia-Herzegovina international arrived at St Johnstone in October when Steven Anderson was sidelined with a dislocated thumb and Frazer Wright was out of action due to suspension.
Saints manager Tommy Wright revealed the decision to free the centre-back was to make funds available for the current transfer window.
Jahic is the second player to exit the Perth side in January after winger Gwion Edwards decided to return to his parent club Swansea.
Wright said: "Sanel is one I would like to have kept and he was willing to stay but I feel that what money we have to strengthen the squad has to be used in other areas."
Jahic made six appearances in his short spell at St Johnstone and he scored his only goal in the 2-0 victory over Livingston in the Scottish Cup in November.