One of the United States’ most prominent competition horse owners, Jane Clark, is resigning as president and CEO of the U.S. Equestrian Team Foundation after revealing that British team gold medalist Ben Maher will ride her top show jumpers.

Clark’s horses have been resting since Mario Deslauriers, who started working for her in 2009, lost the ride on them this summer. Maher has begun riding them, but they won’t start competing again until the 2013 Florida circuit.

Although she considered American riders, Clark said, “I really think that Ben was the best possible rider for these horses at this time. He’s a brilliant rider, and we’re very happy with him. It had nothing to do with flags. It had to do with having the right person for my horses and doing the right thing by them.”

Maher, who tied for ninth individually at the 2012 London Olympic Games on Tripple X, stated on his website: “I am delighted to be riding Jane Clark’s string of horses. I have admired her horses for a long time, so it will be a great honor to ride for her. The new horses will strengthen my current team and enable me to be more competitive at the Top League shows. I will continue to work closely with my existing owners and am really looking forward to working with Jane, whose knowledge of the jumping world is respected around the circuit.”

It’s too early to project the future of Maher’s relationship with Clark’s horses, but she noted that, if they are successful, he could ride her horses on the British team.

While several U.S. owners use foreign riders—for instance, Brazilian rider Rodrigo Pessoa’s 2012 Olympic mount, Rebozo, belongs to Hunter Harrison—Clark felt it would be wrong to remain in her position with the foundation after signing up Maher. She will step down at the foundation’s annual meeting in January.

She recalled the fallout when U.S. Equestrian Federation President David O’Connor announced he would coach the Canadian eventing team and didn’t want to find herself in a similarly “awkward” position.

“This is a similar type situation,” she said. “His loyalty to the U.S. didn’t change; my loyalties to the U.S. haven’t changed.”

She is on the Board of the U.S. Equestrian Federation, occupying the foundation’s seat at the table and would be willing to stay on in that position if the foundation wants her to do it.

Clark has put enormous financial support behind the USET Foundation and been instrumental in helping fund improvements to its historic Gladstone, N.J., headquarters in recent years. The foundation raises money for international training and competition, which goes to the USEF for that purpose. It gave the federation a $2.7 million high-performance grant in 2012.

A season that started with promise for the Clark horses this year ended in disappointment and controversy. Her mare, Cella, who won the $200,000 Gene Mische American Invitational (Fla.) in April, was 13th on the list of nominated entries for the London Olympics. Urico, another of Clark’s horses, stood sixth on the long list for the Olympics after the March selection trials. But the horse’s name was taken off the list after he tested positive for a trace amount of cocaine. Following a USEF hearing, Clark’s barn manager, Bruce Burr, was suspended for two years because he was listed as the trainer.

Clark still sponsors U.S. dressage rider Katherine Bateson-Chandler and U.S. four-in-hand driver Chester Weber, a world championships multi-medalist. She’s also buying horses for Olympic show jumper Leslie Burr Howard, who had worked for her for years and rode a Clark mount to the team silver medal in the 1996 Olympic Games (Ga.).

USET Foundation Chairman Armand Leone wished Clark could have found a U.S. rider.

“I’m disappointed. It’s hard for me to understand the decision, but we’ll move forward,” he said.