Workforce, brilliant winner of last year's Investec Derby and Prix de l'Arc de Triomphe, has been retired to stud.

The four-year-old colt, owned by Khalid Abdullah and bred by his Juddmonte Farms operation, will stand at Teruya Yoshida's Shadai Farm in Japan.

"He's going to Shadai Stud in Japan," said Abdullah's racing manager Teddy Grimthorpe.

"He's been a wonderful horse. To win a Derby and an Arc was pretty exceptional."

Workforce, trained by Michael Stoute, was unable to match his two 2010 Group One successes this season, however.

After making a winning seasonal debut in the Brigadier Gerard Stakes at Sandown in May, he was runner-up in both the Coral-Eclipse Stakes and King George VI And Queen Elizabeth Stakes at Ascot.

His last start was in the Arc but he never looked like repeat last year's triumph and was well-beaten in 12th behind Danedream.

The son of King's Best won four of his nine starts and amassed £3,200,000 in prize money.