( CNN ) -- Rory McIlroy is enjoying the best year of his fledgling golf career , but the U.S. Open champion is already making plans to spread his wings further . The 22-year-old announced on Friday that he is leaving the manager who helped turn him into potentially the next Tiger Woods , as he seeks to push himself to a new level . The world No . 3 is departing Andrew `` Chubby '' Chandler 's International Sports Management , which looks after second-ranked Lee Westwood , Masters winner Charl Schwartzel and British Open champion Darren Clarke . He will link up with fellow Northern Irishman Graeme McDowell , the 2010 U.S. Open champion , at Dublin-based sports agency Horizon as he rejoins the PGA Tour next year . `` I am now keen to move onto the next stage of my career and I feel this will be facilitated by a fresh view and a new structure around me , '' McIlroy said in a statement . `` Therefore I am delighted to be joining Horizon and I look forward to working with my new team . `` I would like to sincerely thank Andrew 'Chubby ' Chandler and his team for their guidance , representation and management over the past four years since turning pro . `` Chubby and his team have played a very important role in my success to date . I have made great progress under their management and for that I will always be grateful . '' McIlroy joined ISM after being the best-finishing amateur at the 2007 British Open , and the company wished him future success . `` It has been an honour representing Rory and we take great pride in the role ISM has played in guiding him successfully through his formative years as a professional golfer , '' it said in a statement . `` Under our management he has grown into an international figure , and he leaves us as a major champion . '' Meanwhile , former world No . 2 Sergio Garcia was in contention to win his first title in three years after taking the halfway lead on his home course at the Castello Masters on Friday . The Spaniard , now ranked 49th , shot a sizzling eight-under-par 63 in the second round to go two shots clear at the Club de Campo del Mediterraneo club where he has played since he was a child . Sweden 's Alexander Noren matched that score to be second on 10-under 132 , two strokes clear of England 's first-round leader Ross McGowan ( 70 ) , Scotland 's Gary Orr ( 67 ) and Australia 's Marcus Fraser ( 64 ) . `` It 's getting there , '' Garcia told the European Tour website . `` It 's not quite there yet -- sometimes I have a little bit of a hard time hitting a draw , but when my little fade works out I can keep it in play . `` At the weekend I 'll try to hit good shots , to putt well and I 'm going to do my utmost . It 's nice to be up there , that 's why we train . It 's even nicer to be there on Sunday afternoon . Alex is right behind me , so I need to keep focused . ''
World No . 3 Rory McIlroy ends three years association with manager Chubby Chandler . U.S. Open champion decides to join compatriot Chandler at Horizon . Chubby Chandler 's company wishes Graeme McDowell future success with his new agency . Sergio Garcia takes two -shot lead at the halfway stage of Horizon Masters .