LONDON, September 27, 2013 (AFP) - McIlroy denied speculation in May he was going to go it alone only for Ryder Cup partner Graeme McDowell to say a few days later the two-time major-winner had in fact decided on his second management change since October 2011.
The 24-year-old Northern Irishman left the International Sports Management (ISM) group run by well-known golf agent Andrew 'Chubby' Chandler just four months after winning his first major championship, the US Open and joined McDowell at Horizon.
But a statement on McIlroy's own website confirmed the split, saying: "Rory McIlroy today (Friday) confirmed he has terminated his contract with Horizon Sports Management and that the details of the termination are in the hands of a legal team....in Dublin, Ireland.
"The golfer's business interests will from now on be managed by Rory McIlroy Incorporated. CEO of RMI will be Donal Casey, an actuary by profession with many years of CEO experience.
"The Rory Foundation for charity will be run by Barry Funston, a business leader and longtime friend of the McIlroy family. Both men will serve on the RMI Board, together with Gerry McIlroy (Rory's father)."
Towards the end of 2012, McIlroy changed clubs and joined up with US sports goods giant Nike in a multi-million pounds deal much criticised by British golf great Nick Faldo who said the deal, however lucrative, risked damaging the players' results on the course.
Later Friday a statement issued by Horizon said the matter was now "regrettably" in the hands of their lawyers.
"Horizon Sports Management notes, with disappointment, the statement issued by Rory McIlroy today. Since October 2011, Horizon has achieved exceptional results for Rory in realising his commercial objectives.
"Under Horizon's management, Rory has signed some of the most lucrative endorsements in sports history. The current management contract has a number of years to run.
"Rory's decision to seek a termination of the management contract with Horizon is now regrettably in the hands of legal advisors. Horizon will be making no further comment."
McIlroy failed to qualify for the Tour Championship on the US PGA Tour last week.
Henrik Stenson's victory took the Swede to fourth in the world rankings and knocked McIlroy down to sixth place.