The car-rental company has issued RFIs via the marketing strategist Procurian and agencies have been invited to submit initial information online.
Initiative, the incumbent, won the account in 2009 after a pitch against Manning Gottlieb and OMD International, which held the UK and European accounts respectively.
The remit includes TV buying, press buying, cinema, outdoor, online media, affiliate management and direct response services.
Hertz, which was founded in the US, claims to be the world’s largest general use car-rental company, operating in more than 8,500 locations in 146 countries.
In 2011, Hertz consolidated its global advertising account into DDB. Before this, its advertising business was handled by Iris Worldwide.
The news of the review follows the announcement in March that Hertz is looking for a global PR agency to handle the brand’s corporate reputation around the world.
Hertz was founded in 1918 by Walter L Jacobs, who started out with a dozen revamped Ford Model Ts.