The former Stirling Albion, Stenhousemuir and Kilsyth Rangers forward joined Livi this summer after a successful season with Queen's Park and now makes the move to Firhill.
Jags boss Ian McCall told the club website: "There were a number of clubs interested in Salim and I’m really pleased he chose to come to Thistle. He is a goalscorer and it says a lot about the boy that 18 months ago he was playing Junior football."