Jeneba Tarmoh will not participate in a runoff against Allyson Felix for the third and final spot on the U.S. team for the 100-meter women's race at the 2012 London Games, USA Track and Field announced Monday.

The runoff -- a winner-take-all race -- was to be held Monday at 5 p.m. PT at Hayward Field in Eugene, Ore.

"We are disappointed that Jeneba has changed her mind regarding her position on the Olympic team," USATF president and chairman Stephanie Hightower said in a statement. "We all worked hard to reach a consensus on the tiebreaker, but we know that Allyson, Carmelita (Jeter) and Tianna (Madison) will represent Team USA well."

Tarmoh informed USATF of her decision via an email that was forwarded to U.S. track's governing body by her agent, Kimberly Holland.

"I Jeneba Tarmoh have decided to decline my 3rd place position in the 100m dash to Allyson Felix," Tarmoh wrote in the email. "I understand that with this decision I am no longer running the 100m dash in the Olympic Games and will be an alternate for the event. As an alternate I understand that I will be asked to run if another 100m runner decides not to for personal reasons, and/or on the 4x100m relay."

Felix said in a statement that she was disappointed by Tarmoh's decision.

"The situation has been difficult for everyone involved. I had accepted the USATF decision and was prepared to run at 5 p.m. I wanted to earn my spot on this team and not have it conceded to me, so I share in everyone's disappointment that this runoff will not happen. All I can do now is turn my focus to London."