Legendary jockey Frankie Dettori revealed he is set to quit Sheikh Mohammed bin Rashid al-Maktoum's Godolphin stable after 18 years.

Dettori rode Godolphin's first Classic winner, Balanchine, in 1994 and had 110 Group One victories for the stable, but the Italian has gradually lost his position as the team's top rider due to the emergence of Mickael Barzalona and Silvestre de Sousa. The 41-year-old, who won nine English Classics with the team, could still ride for Godolphin on a freelance basis, but Barzalona and De Sousa will be the stable's retained riders for 2013.

"Godolphin has been a major part of everything I have achieved in racing," Dettori said "I feel the time has come for a change. My position in the stable has changed a little bit and I need a new challenge. Sheikh Mohammed has been an unbelievable boss to me. He had the confidence to take me on board when I was young and we smashed every record together.

"I will be forever grateful to him for everything he has done for me and for my family," he added.

France's Barzalona, 21, who won the 2011 Derby as a 19-year-old on his debut in the race, joined Godolphin in March and has shared top billing with Dettori since then.

Godolphin's racing manager Simon Crisford added: "Frankie has achieved so much on behalf of Godolphin and has made the difference between winning and losing on so many occasions in the world's biggest races.

"Frankie is looking for a fresh challenge and we felt that the retainer was not really working so this is the best way forward. We have had many great days together and we look forward to working with Frankie in the future and hopefully enjoying more success together."