LONDON — World record holder Paula Radcliffe withdrew from the London Marathon today because of a toe tendon injury.

Radcliffe, a three-time champion in London who also won last year's New York Marathon, is expected to recover in time for this August's Beijing Olympics.

"I am desperately disappointed that I have to pull out of this year's race," said Radcliffe, who won the London Marathon in 2002, '03 and '05 but missed the last two editions because of injury and the birth of her daughter. "I love running in London and this race would have been the perfect test for me before the Olympic Games."

Radcliffe injured her right toe while altitude training at her base in Albuquerque, N.M., London Marathon organizers said in a statement.

"In marathon training there are no short cuts and there is simply not enough time to be in the shape I want to be in to run well in London," Radcliffe said. "Now I must concentrate on being as well prepared as possible for Beijing."

The Olympic marathon will be raced on Aug. 17.

"Of course, it is a major blow to lose Paula from this year's race but we understand that her priority in 2008 is to be in peak condition for the Olympic Games and we wish her all the best for a speedy return to full fitness," London Marathon race director David Bedford said.

Radcliffe dropped out of the marathon at the 2004 Athens Games, but she won the world title in the event a year later in Helsinki, Finland.

In February, Radcliffe won the Laureus award for World Comeback of the Year for winning in New York after two years away from competition following childbirth.

She set the world record of 2 hours, 15 minutes, 25 seconds in London in 2003.

This year's London Marathon, scheduled for April 13, still includes World Marathon Majors champion Gete Wami, Chicago marathon champion Berhane Adere, Constantina Tomescu-Dita and Russian veteran Svetlana Zakharova.

"Even without Paula we will still have a very strong international women's field," Bedford said.

Defending men's champion Martin Lel, Olympic champion Stefano Baldini and world champion Luke Kibet are also slated to run.