Leekens, 70, took charge of Tractor Sazi as a replacement for interim coach Mohammad Taghavi in January.
He started his work on high note in Tractor Sazi but the team faced some problems in the last weeks and finished in fifth place in Iran Professional League and failed to book a place in the 2020 AFC Champions League.
The Belgian trainer has worked as head coach of Belgium, Hungary, Algeria and Tunisia national football teams as well as Belgian clubs Anderlecht, Lokeren, Gent, Club Brugge, Kortrijk, Charleroi, and Excelsior Mouscron.
Antonio Jose da Conceicao Oliveira is a candidate to take charge of Tractor Sazi.