Rory McIlroy and former manager Andrew "Chubby" Chandler at the PGA Championship in August.

Story highlights

World No. 3 Rory McIlroy ends four-year association with manager Chubby Chandler

U.S. Open champion decides to join compatriot Graeme McDowell at Horizon

Chandler's company wishes McIlroy future success with his new agency

Sergio Garcia takes two-shot lead at the halfway stage of Castello Masters

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.”