American gymnast Memmel out of world championships

Gymnast Chellsie Memmel performs her routine on the uneven parallel bars at the 2008 U.S. Olympic gymnastics team trials in Philadelphia, Pennsylvania, June 22, 2008.

LOS ANGELES (Reuters) - American Chellsie Memmel, winner of the 2005 all-round title, is out of this month's world championships in London.

Memmel, a member of the silver medal-winning U.S. team at the 2008 Beijing Olympics, had ankle surgery at the end of last year and has not yet been able to regain top form.

"I have run out of time and I am not quite where I want to be," the 21-year-old told the United States Olympic Committee's official website (teamusa.org) on Friday.

"I haven't been able to do the number of routines and repetitions I need to represent the U.S. at the highest level." The world championships take place from October 13-18.

(Writing by Mark Lamport-Stokes, editing by Tony Jimenez)