Montjeu is on course to bid to end his illustrious career on a high by running in the Breeders` Cup Turf at Churchill Downs.
The four-year-old colt left John Hammond`s Chantilly stable today to fly to the United States in preparation for next Saturday`s 2 million prize.
Owner Michael Tabor`s wife Doreen said this afternoon: 'The horse is on the plane, he`s en route.
'Whether he runs is the second question, but I am sure they will sort it out when he gets there.'
Connections have already paid 60,000 dollars (about £42,000) to secure a place in the field and will have to pay a further 120,000 by 10am on Wednesday if the horse is going to run.
The decision to delay the retirement of last year`s Prix de l`Arc de Triomphe, French and Irish Derby hero was prompted by an impressive gallop on Friday.
Partnered by his regular work rider Michael Dureuil over 10 furlongs, Montjeu drew six lengths clear of his two working companions
Before then it had been rumoured that Montjeu would be retired to stud after being beaten in his last two races.
He had rewarded Tabor`s decision to keep him in training this season with three Group One wins, each time showing his characteristic burst of speed to see off his rivals in a matter of strides.
Highlight was the King George VI And Queen Elizabeth Diamond Stakes at Ascot as he hardly came off the bridle to justify odds of 1-3 in Britain`s most prestigious middle-distance race.
But things started to go awry in the autumn as a minor setback forced him to miss the Irish Champion Stakes.
Back at Longchamp he could finish only fourth behind Sinndar when bidding to become the first repeat Arc winner for 22 years.
And he was beaten by another of the Aga Khan`s colts in Kalanisi when second in the Dubai Champion Stakes at Newmarket a fortnight ago.
Overall he has won 11 of his 15 career starts, recording six Group One victories, and earning over £2.3million in prize money.
Montjeu is to stand as a stallion next year in Ireland, joining the likes of 'iron horse' Giant`s Causeway and his own sire Sadler`s Wells at Coolmore Stud.
Ladbrokes quote Montjeu as the 4-1 joint favourite along with Kalinisi for the Breeders` Cup Turf.
