Members of Delta Air Lines' Skymiles loyalty programme can earn bonus miles and save up to 40 per cent each time they rent a car from Hertz.
The promotion runs until July 31 at participating airport locations worldwide.
General members can earn 200 bonus miles per day, while Gold & Silver Medallion members and Diamond & Platinum members can each earn 300 bonus miles per day.
The discount of up to 40 per cent "applies to time and mileage charges only [and] discounts vary by rental date, location and vehicle type".
The minimum rental period is one day, the minimum rental age is 25, and the offer is valid on all Hertz cars. Reservations must be made at least eight hours in advance and members must quote their Skymiles number at the time of booking.
Full terms and conditions can be read here.