The worst kept secret in golf is finally out in the open, with the news that Rory McIlroy has officially signed a sponsorship deal with Nike.

While the exact length of the deal was not revealed, it has been widely reported to be a 10-year contract worth as much as £150million, making McIlroy one of the biggest earners in sporting history.

McIlroy, previously with Titleist, will now use Nike's full range of clubs, balls, clothing and accessories, and will debut the new gear at the Abu Dhabi HSBC Championship later this week against a field that includes the other leading golf name in Nike colours, 14-major winner and world number two Tiger Woods.

"I chose Nike for a number of reasons," McIlroy said. "It's a company and a brand that really resonates with me. It's young. It's athletic. It's innovative. They are committed to being the best, as am I.

"Signing with Nike is another step towards living out my dream."

Cindy Davis, president of Nike Golf, added: "Rory is an extraordinary athlete who creates enormous excitement with his on-course performance while, at the same time, connecting with fans everywhere.

"He is the epitome of a Nike athlete and he is joining our team during the most exciting time in Nike Golf's history. We are looking forward to partnering with him to take his remarkable career to the next level."

McIlroy is unquestionably the top golfer in the world right now, with eight-shot major championship victories in both 2011 and 2012 and the current World No 1 ranking underlining his credentials.

"If you are going to talk about someone challenging the record of Jack Nicklaus there's your man," said Padraig Harrington, referring to Nicklaus' 18 majors.

"At his age he's probably got 100 more majors where he could be competitive. It would give him a great chance."

While some, including six-time major champion Nick Faldo, have expressed concern over McIlroy's equipment change and the effect it might have on his game, McIlroy was quick to allay such fears, saying back in November: "I think all the manufacturers make great equipment nowadays and it's all very similar.

"A lot of them get their clubs made at the same factories. I don't think it will make any difference.

"I've started the process of trying a few new things. I've tinkered about a little bit with the new ones, enough to feel comfortable going into next season."

Golf 365