O'Neill had agreed a loan deal with a view to a permanent switch for the 23-year-old, but Celtic were unable to give cash guarantees to the player's club Atletico Paranaense after their defeat to FC Basel on Wednesday.
"We had lined him up initially on loan, but with a view to buying him in January," O'Neill said.
"But it has not materialised because the selling club wanted a commitment from us to buy him, and we were not able to give it.
"The buying of anyone would not be on now.
"There is always the possibility of doing a loan deal with someone, but even that is highly unlikely.
"As for reviving the Kleberson deal in January, it will depend on what progress we make. You can take that pretty much as what progress we make in Europe through the Uefa Cup.
"But you never know, Kleberson's club might come back to us before the deadline and say they have changed their minds."
Celtic fans will be desperately disappointed to have learnt that Kleberson would have been at Celtic Park, if not for their shock Champions League exit.
Kleberson has been linked with a move to Britain all summer, with a host of Premiership clubs said to be looking at snapping the Samba star up.
