French energy giant EDF has been unveiled as the second "Premium Partner" of the Paris 2024 Olympic and Paralympic Games.
The company becomes the Games' official electricity and gas supplier.
Jean Bernard Lévy, the group's chairman and chief executive, said the partnership gave EDF the chance to "rally" its strengths "to help boost the success and fantastic example set by these Games in terms of environmental responsibility".
Tony Estanguet, Paris 2024 President and International Olympic Committee (IOC) member, said the two parties were together "taking up the challenge of organising the most environmentally friendly Olympic and Paralympic Games possible".
EDF, he added, was "a company with roots in the day-to-day lives of French people".
This would "help us achieve our ambition of making sure the Games are open to as many people as possible".
The timing of the deal, just a day after the IOC's unveiling of Airbnb as a new global sponsor, is opportune.
That deal is seen as controversial in Paris, not least by Mayor Anne Hidalgo, who faces a tight-looking race for re-election next March.
Hidalgo is reported by the news agency Agence France-Presse to have warned the IOC about the "risks" of its Airbnb deal in a recent letter.
She is said to have told IOC President Thomas Bach of her "total determination" to tighten rules on tourist rentals in the French capital, which are believed by local officials to be a factor in pushing up rents.
Hidalgo's campaigning for environmental initiatives is also believed to have been partly responsible for the French oil company Total's decision earlier this year to opt out of sponsoring Paris 2024.
EDF's categorisation as "electricity and gas supplier" appears, however, to leave a way open for Total to reconsider at a later date by possibly purchasing the "energy" sponsorship category, or something similar.
Marlène Masure, Paris 2024's executive director of business development and partnerships, told insidethegames exclusively in June that the oil sector might yet provide a sponsor for Paris 2024.
"My commercial vision is yes, we could and we should," Masure - for whom the EDF deal represents a feather in the cap - said.
"But I am not the only one involved in this decision.
"We would still be proud to sign a deal with Total.
"For the moment, the conversation is stopped.
"But oil was not an issue in terms of the category."
Paris 2024 is budgeting to raise $1.125 billion (£870 million/€1.02 billion) from domestic sponsorship in all.
Its initial deal, with French banking group BPCE, whose brands include Banque Populaire and Caisse d’Epargne, was announced as long ago as Septermber 2018.
EDF is believed to be considering major structural changes at the behest of the French Government.
It is engaged in a multi-billion-dollar investment programme to prolong the life of some of France's 50-plus nuclear power stations, but must also invest in renewables as part of a drive to cut the percentage of nuclear electricity used in France from more than 70 per cent to 50 per cent.
The Financial Times has reported that a plan has been devised to create a Government-owned mother company called EDF Bleu to contain nuclear and hydroelectric assets, while a subsidiary - EDF Vert - would include renewables, networks and services.
According to the FT, this plan is known as Project Hercules.