ONE of the key advisers who helped broker golfer Rory McIlroy's $100m (€74m) Nike contract left the Dublin agency that secured the deal following a dispute over a €500,000 "success fee".
McIlroy (24), who this week launched legal action against Horizon Sports Management, his former agent, has claimed that the success-fee row resulted in the departure from Horizon of consultant Donal Casey.
The former world number one is suing Horizon and two other linked companies – the Malta-based Gurteen and Canovan Management Services, which is based in Dublin – in an attempt to recover some of the $6.8m (€5m) that he has paid in fees.
The row over the success fee has been placed at the heart of the complex lawsuit by the golfer, who claims that his management by Horizon suffered as a result of the "serious and important" dispute over the fee that was sought by Mr Casey.
An actuary and former head of strategy at Horizon, Mr Casey is now CEO of Rory McIlroy Incorporated (RMI), which is managing McIlroy's interests after a high-profile split between the sports star and Horizon last month.
Horizon, which is counter-suing the golfer, secured 20pc of McIlroy's overall earnings from the five-year Nike deal, which expires in 2017.
The internal Horizon dispute over the Nike contract, which also features disagreements over whether Mr McIlroy's golf bag should have been included in the deal, is set to become a major issue in the litigation, which is due to be heard at the Commercial Court in October 2014.
It is understood that Horizon, led by managing director Conor Ridge, refused to pay Mr Casey €500,000, offering a sum of some €200,000 instead.
Central to this aspect of the legal action by Mr McIlroy is whether there was an agreed success fee between Mr Ridge and Mr Casey prior to completion of the Nike deal.
Neither Mr Casey nor Mr Ridge were available for comment last night.
In court papers, Mr McIlroy claims that he was not notified by Horizon and Mr Ridge of "a serious and important dispute" between Mr Ridge and Mr Casey over the success fee.
Mr McIlroy said Mr Casey's departure resulted in the loss of "key skills and know-how" to his management team.