Sheikh Joaan Al Thani's Al Shaqab Racing has purchased a 50% interest in the Coolmore-owned Ruler Of The World, last season's Epsom Derby winner.

The four-year-old Galileo colt will remain in training with Aidan O'Brien and will continue to be ridden by the Ballydoyle handler's son, Joseph.

Ruler Of The World is due to contest the Dubai World Cup at Meydan on Saturday but will now run in the colours Al Shaqab Racing.

Al Shaqab's racing advisor Harry Herbert said: "Al Shaqab is delighted to be in partnership with John Magnier, Michael Tabor and Derrick Smith and we are extremely excited to be participating in Saturday's World Cup."

A statement posted on www.coolmore.com read: "Al Shaqab Racing has purchased a significant interest in last year's Epsom Derby winner Ruler Of The World.

"The son of Galileo will run in the colours of Al Shaqab Racing in partnership with the Coolmore triumvirate of Tabor/Smith/Magnier.

"He will remain in training with Aidan O'Brien at Ballydoyle and will continue to be ridden by Joseph O'Brien.

"Ruler Of The World who will retire to Coolmore at the end of his racing career is due to begin his season in Saturday's Dubai World Cup where he heads a team of six trained by Aidan O'Brien."

Herbert confirmed a deal had been struck for 50% of the colt.

"It's tremendously exciting and the Sheikh is thrilled," said Herbert.

"It's been a very recent development, just over the last two or three days, and Al Shaqab have 50 per cent.

"But he'll remain with Aidan O'Brien and will be ridden by Joseph O'Brien, Coolmore were keen for that to be the case.

"When he retires, Al Shaqab will also receive 50 per cent of his stud value.

"He is a horse that Sheikh Joaan has always liked and pinpointed him as a horse he'd like to be involved with, especially with this weekend in mind. It's great to be involved in races like this.

"He looks fantastic and has been vetted this morning, he travelled over especially well. Whatever happens on Saturday, it is a long season and he'll be a great addition.

"He's beautifully bred and it is not easy to get involved with a Derby winner.

"Sheikh Joaan spoke to John Magnier about acquiring a stake and it went from there.

"Hopefully it is the start of a great partnership as Al Shaqab also have a share in a Galileo two-year-old with Coolmore.

"If, for whatever reason, at some point in the season Joseph is unavailable to ride then Frankie (Dettori) will step in."