Gregory Benoist has chosen Ectot over Avenir Certain as his mount in the Prix de l'Arc de Triomphe at Longchamp.

The Elie Lellouche-trained Ectot burst into the picture for the Arc on Sunday week with victory in the Prix Niel on Arc Trials day.

Christophe Lemaire will partner the Jean-Claude Rouget-trained Avenir Certain, winner of the French 1000 Guineas and the French Oaks under Benoist.

Gerard Augustin-Normand part-owns both horses and Al Shaqab Racing recently bought a major interest in Ectot, meaning Frankie Dettori could have been in line for the ride had Benoist chosen Avenir Certain.

Augustin-Normand's racing manager Silvain Vidal said it had not been an easy decision for the jockey.

"Both horses are very well and it was very hard for Gregory to choose between them," Vidal said.

"Gregory was in Pau on Tuesday to ride Avenir Certain in a very good gallop, so it was very hard to choose one, but he did.

"Ectot is not difficult to ride, but has a lot of character, so for the team I think this was the best decision.

"Avenir Certain is very easy to ride and Ectot could be a little bit tense in the race.

"Gregory Benoist has always ridden him, so he knows him very well. He won his first Group One race on him (the Criterium International at Saint-Cloud in November) as well."

Ectot and Avenir Certain are vying for outright second-favouritism in the Arc behind the John Gosden-trained Oaks and King George winner Taghrooda.

The John Gosden-trained filly heads the market despite losing her 100 per cent record with a shock defeat in the Yorkshire Oaks last month.

However, Taghrooda appears to have put that behind her and she pleased Gosden and jockey Paul Hanagan in a racecourse gallop at Newmarket on Wednesday.