New England Sports Ventures have completed the £300million takeover of Liverpool.
The owners of the Boston Red Sox have taken control of the club after Tom Hicks and George Gillett were defeated in their legal battle to stop the takeover.
An NESV source said: "The deal has been done."
The purchase of Liverpool brings an end to Hicks and Gillett's three-and-a-half years at the club but almost certainly not an end to the saga.
Hicks and Gillett have promised to sue for £1billion in damages, claiming the sale to NESV was "illegal", and have threatened to launch another destabilising legal action.
A statement from Hicks' and Gillett's New York representatives announced they were suing over "an extraordinary swindle" but appeared to accept that they will have to relinquish ownership of the club.
Steve Stodghill, the Texas lawyer representing the duo, said: "This outcome not only devalues the club but it also will result in long-term uncertainty for the fans, players and everyone who loves this sport because all legal recourses will be pursued.
"Mr Hicks and Mr Gillett pledged to pay the debt to RBS so that the club could avoid administration that was threatened by RBS. That offer was rejected.
"It is a tragic development that others will claim as a victory. This means it won't be resolved the way it should be resolved."