The Renault car company has sold its remaining shares in the eponymous Formula 1 team, which will be renamed Lotus Renault in 2011.
Renault was left with a 25% shareholding in the team in 2010 after selling the remainder to private investment group Genii Capital.
Those shares have been sold to Genii and will be then taken by Lotus Cars, which is owned by Proton.
The move means there will be two F1 teams in 2011 with Lotus in their name.
The team that competed as Lotus Racing in 2010 will be renamed Team Lotus after buying the historic rights to the name under which Lotus raced from the 1960s until collapsing with financial difficulties in 1994.
Team Lotus boss Tony Fernandes, the owner of the Air Asia airline, is in dispute with Proton over the rights to use the Lotus name in F1.
The cars produced by Lotus Renault will still be called Renaults - changing that would need the permission of all the other F1 teams.
A Renault F1 statement said: "Lotus plc will become a major equity partner of Genii Capital in Lotus Renault GP, and the two parties have concluded a title sponsorship agreement that will run until the end of the 2017 season."
It appears as if both teams plan to run their cars with black and gold liveries, reflecting the historic John Player Special sponsorship of Lotus in the 1970s and 1980s.
Renault and Lotus battling on track during a test session in 2010
Renault's statement said: "For 2011, the Lotus Renault GP cars will race in a new interpretation of the iconic black and gold colours that were last used when Lotus and Renault joined forces in the 1980s.
"This livery, which has been on the drawing board for over two months in order to reinterpret its iconic graphic signature to suit modern media requirements, is sure to strike a powerful chord with the sport's enthusiasts around the world."
Lotus Racing announced its plans to use a black and gold livery at the season-ending Abu Dhabi Grand Prix in November.
Renault's statement continued: "Renault will continue its strong support of the team with which it won the 2005 and 2006 world championships, as a supplier of engines and technological and engineering expertise.
"Reflecting this technological support, Lotus Renault GP will continue to compete with the Renault chassis name and Renault will enjoy pre-eminent brand exposure on the livery."
Proton's decision to buy into the Renault team and promote its Lotus brand is the latest development in ambitious plans for future expansion by Lotus.
At the recent Paris Motor Show, it announced plans to build a number of new road cars and it has also said it will compete at Le Mans and in IndyCar racing in the US.
The chief executive officer of Group Lotus, Dany Bahar, said: "I can think of no better platform for automotive brand communications than motorsport and F1 is the very pinnacle of open-wheel racing.
"We're well aware that there has been a lot of controversy around the usage of our brand in F1 and I'm delighted to be able to formally clarify our position once and for all: we are Lotus and we are back."
Team Lotus boss Fernandes responded on his page on social network site Twitter : "Dany Bahr has done us a favour. Never felt better about our future and Team Lotus.
He added: "Looks like [they're] trying to hijack our black and gold idea."
Renault's decision to sell its remaining shares in the team ends a 10-year involvement in F1 as a team owner.
The French car company has been a competitor since buying Benetton Formula in 2000 and renaming it Renault for the 2002 season.