Julian Segal to step down after a decade at the helm.
Lion, Coca-Cola Amatil, Nufarm and Inghams all made the top 30.
The company found that 250 of its franchise employees were being underpaid.
Petrol giant plans company owned service stations by 2020.
Fair Work Ombudsman’s investigation relating to the Caltex network remains ongoing.
Petrol franchisee allegedly falsified records of wage rates paid to overseas workers.