Renault is to return to Formula 1 as a constructor after deciding that it will take over the Lotus team.
The French car giant had been debating the decision as recently as last weekend but is now committed.
Chairman Carlos Ghosn said: "We had two options: come back 100% or leave. After a detailed study, I decided Renault will be in F1 from 2016."
Renault said its takeover of Lotus had not yet been completed but will be done "in the shortest timeframe possible".
However, the company added that the "principal contracts were signed" on Thursday.
The move ends months of speculation and secures the future of the team based in Enstone in Oxfordshire, which has in its history won four world drivers' titles, two as Benetton with Michael Schumacher in 1994 and 1995, and two as Renault with Fernando Alonso in 2005 and 2006.
Renault sold the team to investment group Genii Capital at the end of 2009 after deciding to quit as a constructor but remained involved as an engine builder.
Ghosn has decided that Renault will be best served by running its own team, a conclusion reached following the breakdown of its relationship with Red Bull.
Renault and Red Bull won four world driver and constructor doubles together from 2010-2013 but tension grew following the engine builder's inability to produce a competitive power-unit under the new turbo hybrid formula introduced at the start of 2014.
Red Bull had a contract with Renault until the end of 2016 but broke this off in the summer in order to seek a different engine.
But after being rejected by Mercedes and Honda and failing to secure a satisfactory deal with Ferrari, Red Bull will again use Renault engines next season, but as a customer not a factory partner.
Red Bull's Renault engines will be given a different name in order to distance the team from Renault. The former champions hinted on Thursday that they would be branded after their new sponsor, the luxury watchmaker TAG Heuer.
Renault's buy-out of Lotus was in doubt as recently as Saturday following a row over prize money with F1 commercial boss Bernie Ecclestone.
But an agreement was reached at the 11th hour and that was enough to convince Ghosn to go through with the deal, which sources say commits Renault to F1 until 2024.
Ghosn said: "The final details supplied by F1's main stakeholders gave us the confidence to accept this new challenge. Our ambition is to win - even if it will take some time."
The decision to return with its own team was based on the lack of exposure Renault received despite its success with Red Bull.
A Renault statement said: "As a full team, Renault will take maximum benefit from its victories. The payback as an engine supplier proved to be limited.
"The return on the investment necessitated by the new engine regulations and the return in terms of image were low."
Renault staff have been working with Lotus for some months on the presumption the takeover would eventually be completed.
Sources say experienced engineer Bob Bell, who was technical director of world champions Mercedes until the end of last season, is to take on a role overseeing both the chassis design operation in the UK and the Renault Sport engine facility in Viry-Chatillon near Paris.
Bell, who was managing director of Renault F1 before moving to Mercedes, has already held meetings with Renault and Lotus staff as the team plan the build of next year's car.
The Renault drivers for next season will be Venezuelan Pastor Maldonado and British rookie Jolyon Palmer, who was the Lotus reserve driver this season. Both drivers were signed by Lotus while the Renault takeover was still in doubt.
The role of team principal is expected to be taken by Frenchman Frederic Vasseur, the boss of the successful ART team in the GP2 feeder category.