The ruler of Dubai and his son, Sheik Majid, will compete for the United Arab Emirates team in next Wednesday's Kentucky Cup at Lexington.
Sheik Mohammed and his sons have been active participants in endurance racing many years.
The report said the race at Lexington is sponsored by the Emirates Equestrian Federation and is attracting riders from more than 20 countries preparing for the Endurance World Championship at the 2010 Games.
Spain's Maria Alvarez Ponton, the current world champion, also will compete.
Next week's test event at the Kentucky Horse Park features 75-mile and 100-mile races.
Pregnant Mila Kunis wins 'Best Villain' at MTV Movie Awards
Pistorius testifies he didn't consciously pull trigger when he shot girlfriend