The IHRC had previously expressed concerns over the $17.3bn deal but, following financial promises from Eldorado, granted regulatory approval.
In New Jersey, however, that same approval is yet to be forthcoming.
Having originally scheduled a decision for Wednesday, the process was further held up after the New Jersey Casino Control Commission received petitions from Hard Rock Atlantic City and Ocean Casino Resort.
Later, commissioners decided not to allow the competitors to intervene.
But the move was still effective in, at least temporarily, delaying a final decision on Eldorado's acquisition of Caesars.
The Indiana Gaming Commission and Nevada Gaming Commission had recently given the deal their respective approvals, although in Indiana, Eldorado has been told by the regulator to sell three casinos before the end of the year.
