Mr Carroll has sold half of his stake to JDH Acquisitions, the investment vehicle controlled by the Doyle sisters Bernie Gallagher, Anne Roche and Eileen Monahan, and has given an irrevocable undertaking to sell the remaining shares.
The deal will push the 48% stake owned by the Doyles and their associates past the 50.1% required to take the company. It also ends the hopes of Sean Dunne, who has a 28% stake in Jurys, of making a winning bid himself.
Mr Dunne, who is buying almost five acres of prime Dublin land from the Jurys Doyle group in the Ballsbridge area of Dublin for €260 million, had harboured takeover plans. He hired top corporate finance executive Richard Keatinge to advise him.
It is now expected that Mr Dunne will sell his stake to the Doyles, making a €20m profit on his investment.
Mr Carroll, the owner of property companies Dunloe Ewart and Zoe Developments, will net a tidy profit himself by selling his stake. He has sold at €18.90 a share the same price offered by JDH Acquisitions for the entire company.
Mr Carroll bought into Jurys in September, buying shares at prices between €17.80 and €18. He will net around €5m in profit.
The sale by Mr Carroll to the Doyles ends a six-month takeover battle, sparked by the interest by Gresham Hotel owners Precinct Investment.
Several developers, including former Revenue inspector Derek Quinlan (who runs a €5 billion investment portfolio) and Clarion Hotels owner Paddy Kelly, expressed interest.
But after the withdrawal of Precinct it was the family of PV Doyle, who built much of what is now Ireland's largest hotel chain, who have gained control.
The Doyles are backed by long-time associates Vincent Beatty and Elizabeth Nelson and should be able to complete the takeover quickly once a deal with Mr Dunne is struck.
They are expected to move with plans to sell the remaining hotel in on the Ballsbridge and Jurys Montrose.
The cash raised by these sales and the €260m from the five acres, should finance much of the €1.2bn takeover, leaving the hotel group with little debt to hinder expansion plans.
One man who could lose out is Paschal Taggart, the chairman of Bord na gCon. He bought just under 2% of Jurys shares at €19.20 a share. Unless he strikes a deal with the Doyles, he is sitting on a small loss.