The Automobile Club de l'Ouest believes that the merger between Grand-Am and the American Le Mans Series will make international sportscar racing stronger.
ACO president Pierre Fillon, whose organisation licenses the Le Mans name to the ALMS, said the move had "become necessary to enable endurance racing to continue to evolve".
He said the merger, which will come into force in 2014, "will reinforce the presence of endurance racing on the international scene".
A statement from the ACO read: "The ACO is delighted about this merger, which will increase the already large audience for endurance in North America and at the same time boost its international impact.
"The quality of the two organisations combined is a guarantee of confidence concerning the perpetuation of the values and prestige of the Le Mans 24 Hours on the American continent."
Fillon said he would be meeting the bosses of the new organisation, which include ALMS founder Don Panoz and series boss Scott Atherton, to start working with them on the new series.
The new championship, which has yet to be given a name, will retain a class for the Le Mans GTE class, it was confirmed at the official announcement of the merger.
However, Panoz, who is to be vice-chairman of the new organisation, as good as said that there would be no LMP1 class in the new series.
Panoz stated that he intended to find a way for successful teams in the new series to be able to win guaranteed starting spots for the Le Mans 24 Hours.
The first and second-placed teams in the ALMS LMP1, LMP2 and GT categories gain entries for Le Mans, along with the class winners at the Petit Le Mans enduro at Road Atlanta.