Indian Oil Corporation (IOC) will commence marketing of diesel and petrol additives of the French oil major ELF in Chennai starting this month and later spread out to market them in other major metros like Mumbai, Delhi and Calcutta and other major cities in the country. The move comes in the wake of an IOC tie up with ELF last week by which the Indian oil major and Fortune 500 company has the exclusive right to market ELF brand of diesel and petrol additives.