English Derby winner Ruler Of The World will have to defy barrier 12 if he is to win the Dubai World Cup at Meydan on Saturday, when he will be sporting new colours.

Al Shaqab Racing has purchased a 50 per cent share in the horse and he will race in Sheikh Joaan's grey silks.

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.

"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," Al Shaqab's racing advisor Harry Herbert said.

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

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

Last year's winner Animal Kingdom also started from stall 12 so the berth is no barrier to success.

Ed Dunlop's Red Cadeaux, second 12 months ago, fared even worse and will jump from 14 in the 16-runner field, with William Haggas-trained Mukhadram next door in 13.

Sir Michael Stoute's Hillstar fared better in seven, with Andrew Balding's Side Glance in nine.

Hong Kong raiders Akeed Mofeed and Military Attack have drawn barriers four and eight respectively.