The undefeated Reliable Man will have three Aidan O’Brien-trained runners, headed by Irish Derby winner Treasure Beach, among his opponents Thursday in an appealing edition of the Group 1 Grand Prix de Paris at Longchamp.Reliable Man, a Dalakhani colt trained by Alain de Royer-Dupre, only made the races this spring, winning minor events at Saint-Cloud and Chantilly before upsetting the Prix du Jockey Club (French Derby) on June 5 at Chantilly. The runner-up in that race, Bubble Chic, also is among the seven 3-year-olds left in the Grand Prix de Paris after final declarations were announced TuesdayRoyer-Dupre left open the possibility of a late scratch if the Longchamp course comes up fast, but conditions as of Tuesday were good-to-soft, with the course to undergo watering before Thursday’s race.Reliable Man won the French Derby over 11 furlongs, but has yet to travel the 1 1/2 miles of the Grand Prix de Paris, though Royer-Dupre has said the distance is a non-issue. Treasure Beach, however, already is a proven 1 1/2-mile-horse, with two wins from three recent starts at the distance. Treasure Beach beat the promising colt Nathaniel around sharp turns at Chester, took a heart-breaking head loss to Pour Moi in the English Derby at Epsom, and most recently won the Irish Derby at the Curragh, a galloping course with gentler turns. Treasure Beach, a Galileo colt, has never been worse than third while winning half his eight starts, though it may be no easy task to turn in a fourth straight top effort in 2011. O’Brien swept the top three Irish Derby placings, and runner-up Seville also is back in action Thursday at Longchamp. Seville ran poorly in the English Derby, checking in a distant 10th, but has been first or second in his five other starts. O’Brien’s third entrant, Marksmanship, has raced only twice, winning his debut at the Curragh in April and finishing a somewhat troubled seventh June 16 in the Group 3 Tercentenary Stakes at Ascot. Bubble Chic, the French Derby runner-up, is working on a streak of six straight second-place finishes. Bubble Chic has some quality, however, with a second-place finish to Pour Moi in his race before the French Derby.Also on Thursday’s card is the Prix Maurice du Nieuil, a Group 2 for older horses at 1 3/4 miles.