August 20 - Britain's Paula Radcliffe (pictured) today withdrew from the marathon at the World Championships in Berlin because he does not want to jeopardise her chances of running at the London 2012 Olympics.

The 35-year-old world record holder had been hoping to line-up to try to regain the title she won in Helsinki in 2005 and the signs looked good when she won the New York City Half Marathon last Sunday in 69min 45sec.

It was her first race since recovering from an operation on a toe in March.

But she does not believe she has recovered sufficiently to line-up for a race over 26.2 miles.

Radcliffe said: “I am devastated that I wasn’t able to be ready in time to represent Britain here in Berlin, especially having got so close in such a short time frame.

"However after having the surgery to successfully put the years of injury behind me it is very important to me that I come back to racing often and winning at 100 per cent and continue strongly and successfully through to London 2012.

"It has been great to be here and to spend time with the team, which has performed so well so far, and I look forward to being part of it again in the near future.

"Running in New York this weekend was a necessary part of the process to ascertain my race fitness and after speaking with my coaching and medical team, I knew I was sadly just not quite ready.”

Radcliffe's career has been overshadowed in the last five years by injury.

She was unbeaten until the 2004 Olympics in Athens when illness caused by a reaction to medicine she was taking for an injury forced her to drop out of the race when she had been the shortest-priced favourite of the Games.

Then last year her build-up to the Games in Beijing was disrupted by a fracture to her femur and, although she raced, she finished a disappointing 23rd.

Afterwards she vowed to bounce back and win the Olympic medal that has so far eluded her at London in 2012.

UK Athletics head coach Charles van Commenee said: “To lose an athlete of Paula’s calibre is disappointing to say the least.

"She won the World Championships in 2005 and a fit Paula would clearly be in contention to regain that title, but she has taken that difficult decision and we have to respect that."