The agency is likely to move either to a new development at 40 Chancery Lane, WC2 or a property on Clerkenwell Road, part of which used to be occupied by the nightclub Turnmills.
Other Publicis Groupe agencies that are located on the same site on Charlotte Street, including Kitcatt Nohr Digitas and Starcom MediaVest Group, will also move to one of the new locations.
The move follows the redevelopment of the 80 Charlotte Street address by landlord Derwent London. The property company also owns the two new sites that the Publicis Groupe agencies will occupy.
Derwent said that the Chancery Lane offices, which will be ready by July 2014, had been let for £5.7 million a year for 20 years. The rent on the Turnmill development on Clerkenwell Road will be £3.1 million a year.
The Publicis agencies will continue to occupy their existing offices until the new properties are ready to occupy.
Saatchi & Saatchi moved to Charlotte Street in 1975 following its takeover of rival ad agency Compton.