Rory McIlroy is officially a free agent when it comes to golf equipment.

McIlroy and Acushnet Co., which has supplied the 23-year-old star from Northern Ireland with Titleist and FootJoy gear since he turned pro five years ago, said Tuesday they will not extend their relationship after this year.

The announcement allows McIlroy to pursue a lucrative endorsement contract, with strong indications that he will sign with Nike in a deal that one industry observer estimated at $20 million a year. That would give Nike golf's two biggest stars in McIlroy and Tiger Woods, who has been with the swoosh since he turned pro in 1996.

McIlroy has established himself as the No. 1 player in the world this year, when he won four times and captured the PGA Championship at Kiawah, giving him eight-shot wins in two major championships. He won the PGA Tour money title, and is closing in on winning the European Tour money title.

This is the second time in the last 10 years that Acushnet, which has a history of fiscal prudence, has not stood in the way of a No. 1 player going after big money. Woods, who had an equipment deal with Titleist when he turned pro, left for the Nike golf ball in 2000 and then the Nike golf clubs in 2002.

Phil Mickelson won his first Masters with Titleist in 2004, and the Fairhaven, Mass., company let him out of his contract later that summer to sign a lucrative deal with Callaway.

"Our goal has been to provide Rory with the best equipment and service that would help him be the best player he could possibly be," Acushnet chief executive Wally Uihlein said in a statement. "He has been a great ambassador for the Titleist and FootJoy brands, and in turn, we are proud of how our equipment has contributed to his success. We wish Rory all the best, both personally and professionally, going forward."

McIlroy, who defeated Woods in an 18-hole exhibition in China on Monday, thanked the Acushnet staff for "five very exciting and successful years."

"I will always appreciate the contribution Titleist has made in helping me become the player I am today," McIlroy said.

Not since Woods has a player had this much potential at such a young age. McIlroy was 19 when he won the Dubai Desert Classic for his first win as a pro, and he followed that with a 62 in the final round to win at Quail Hollow for his first PGA Tour win.

McIlroy shattered U.S. Open scoring records last summer at Congressional to win by eight shots, and when he won his second major at Kiawah Island in August, he became the youngest player since Seve Ballesteros in 1980 with two majors. Only five players have won majors by at least eight shots since 1976 -- three by Woods, two by McIlroy.

They have become friends in recent months. They were in the same group five times during the FedEx Cup playoffs, and the conversation came easily. That led to the 18-hole exhibition on Monday, the first time Woods has agreed to a head-to-head match since the old "Battle at Bighorn" days against Sergio Garcia.

McIlroy won by one. Walking off the fourth hole, McIlroy even took one of Woods' Nike clubs and took a few practice swings.

Now, it appears likely both will be using the same equipment next year.

"We are declining comment on rumors and speculation," Nike spokeswoman Beth Gast said.

McIlroy is not playing the HSBC Champions this week in China. He will close out his European Tour season starting the following week with the Singapore Open, the Hong Kong Open and the DP World Tour Championship in Dubai. He would have two months until his next tournament in Abu Dhabi, giving him time to test new equipment.

McIlroy has gone through a series of changes since winning his first major last summer at Congressional. He left agent Chubby Chandler a year ago and signed with Conor Ridge of Irish-based Horizon Sports Management. He took up membership on the PGA Tour, where he is a lock to be voted player of the year. Changing the very tools he uses will be the biggest change of all.

Still to be determined is how any deal with Nike would affect the rest of McIlroy's deals. He has endorsements with Jumeirah Estates, Oakley, Audemares Piguet and Santander bank. Nike typically prefers a clean look for its athletes, with rare exception. Woods and Anthony Kim had separate endorsements for their golf bags.

Even as McIlroy was getting courted by other companies, Titleist did not put up a big fight. The company has a history of putting the brand before the player, as it did with Woods, Mickelson, David Duval after he reached No. 1 in the world and Sergio Garcia.

It prides itself on having the most tour players use its golf ball, though it also has some 80 players around the world under contract to use its golf balls and golf clubs. This year might have been particularly costly, however, especially with incentive clauses in the contracts. It had six players from the top 16 in the world as full staff players -- McIlroy, Adam Scott, U.S. Open champion Webb Simpson, Jason Dufner, Steve Stricker and Nick Watney.