There has been speculation the two clubs have already agreed a deal, which would be worth around £10million, to make Carson's year-long loan a permanent transfer.
But O'Neill insisted that was "mere hearsay" although he is a big fan of Carson who hit the headlines for the wrong reasons after his costly blunder as England lost their Euro 2008 qualifier with Croatia.
"Of course, that doesn't mean that you couldn't start talking about something beforehand (the end of the season) and I'm aware Rafael Benitez mentioned something about it a week or so ago.
"But Liverpool haven't spoken to us - and haven't spoken since Scott was capped for England."
O'Neill added: "I will look at the situation and Liverpool will be very much in the driving seat because they can dictate what the player is going to cost.
"But there is no agreement on a fee. It is as simple as that. The rest of it is hearsay."