This is news that could surprise the Paris running world: after almost three decades at the helm, Amaury Sport Organisation (ASO) could lose the organization of the Marathon de Paris and the Semi-Marathon de Paris from 2027. According to Le Parisien, the city of Paris would opt for the Cadence consortium, made up of Keneo, OSE and an agency from the Havas group, to take over the concession for the two races. An unexpected rupture, even though the rumor had been circulating for months behind the scenes.
The concession was due to expire and needed to be renewed for 2027. Three consortia were in the running: Cadence (Keneo, OSE, Havas), the defending champion ASO, and a third group made up of Playground, Infront and Oconnection. It is ultimately Cadence that the City of Paris, owner of the Semi-Marathon and Marathon de Paris brands, would select. ASO, which has organized these events since 1998, thus finds itself edged out of a marquee event it had helped establish in the global sports calendar. A source familiar with the matter told Le Parisien that the move was “quite surprising”: that an event “that has been running for years” would change hands.
The Cadence consortium is no stranger to the Paris racing scene. OSE, one of its members, already runs the Eco-Trail de Paris, a fixture in the Île-de-France running calendar. Keneo adds sports-event know-how, while the Havas agency strengthens the communications and marketing aspect of the dossier. If the Paris City Council approves this choice at its late-May 2026 session, Cadence would manage both events for four years, through 2030.
That's obviously the question on everyone's lips. For the 2026 edition, nothing changes: ASO remains in charge, and the Paris Marathon 2026 just took place with 58,853 marathon runners and 50,000 in the half, a world record. The handover would therefore only occur starting in 2027. For runners, concrete changes are still to be defined: course, registration procedures, race atmosphere... All of this will depend on the choices Cadence makes once the concession is officially in hand. It’s reasonable to expect that a new organizer will want to stamp its mark, bringing fresh ideas on communication, logistics, or the participant experience.
The change is conditioned on the vote by the Conseil de Paris, slated for late May 2026. Until the vote takes place, nothing is decided. But if the decision is confirmed, it will stand among the most significant transitions in the history of running in Île-de-France. To be followed closely.
