“This agreement marks a new chapter in the history of Strasbourg as the consortium is committed to accelerating sustainable investments in the growth of the club,” the BlueCo consortium said in a statement.
“(This includes) the first team and in the academy, in the continuity of the project implemented by Marc Keller, who will remain chairman of the club, supported by his current management team.”
The consortium led by American businessman Todd Boehly and US-based Clearlake Capital endured a torrid first year in charge of Chelsea.
They sacked managers Thomas Tuchel and Graham Potter before a miserable end to the campaign under interim boss Frank Lampard.
Chelsea’s 12th-place finish was their worst since 1994 despite a spend of more than £500 million ($624 million) on new players in the new owners’ first two transfer windows.
They have since hired Mauricio Pochettino as their new coach.
Boehly is also the co-owner of the Los Angeles Dodgers baseball team and the consortium also boasts shares in NBA heavyweights, the LA Lakers.
– ‘New dimension’ –
Strasbourg endured their own struggles last season, finishing just two places and five points above the relegation zone.
They were an impressive sixth just 12 months earlier.
A source told AFP that the US consortium has bought almost all of the Strasbourg club shares.
However, he was unable to reveal the full value of the deal.
Strasbourg are the fifth Ligue 1 club to pass into American ownership after Marseille, Lyon, Toulouse and Le Havre.
“It’s an important day for Strasbourg,” said Keller.
“We have built a healthy, well-managed club at all levels.
“But we were aware that we had reached the ceiling of our model, and that if we wanted to continue to advance the club into a new dimension, we had to be accompanied by a solid structure capable of supporting our development and our ambition.”
He added: “I, therefore, welcome a new strategic investor, with whom we will accelerate the club’s ambition to build the Strasbourg of tomorrow.”
A source at the club said there “will be no affiliation with Chelsea”.
“There will be a common shareholder but separate sports departments. There may be collaborations but that will not be the priority.”
Supporters had feared that Strasbourg, declared bankrupt in 2011 and demoted to the fifth division, would become just a farm team for Chelsea.
“The new majority shareholders are investing in Marc Keller’s project to give him the means to progress,” added the source.
“If Strasbourg does nothing, the club will drop in the hierarchy. We must therefore take preventive measures today to allow the club to maintain its place.”