London: Haile Gebrselassie says the London 2012 Olympics is his "last big goal", after announcing that he's reversing his decision to retire from competitive running.

Just eight days after pulling out of the New York Marathon with a knee injury and then declaring tearfully that he was quitting the sport, the 37-year-old Ethiopian posted a message on his Twitter account to announce a U-turn.

"First, I want to thank you for all your support and great responses," he wrote. "After a few days in the countryside, I could take some decisions. Running is in my blood and I decided to continue competing.

"My announcement in New York was my first reaction after a disappointing race. When my knee is better again I will start focusing on my next race."

His decision is good news for organisers of the Tokyo Marathon, Gebrselassie's next scheduled race in February, and even better news for the London Olympics, where the presence of the marathon world record-holder will add star quality to one of the signature events of the Games.

Burning ambitions

The Ethiopian's long-time manager, Jos Hermens, said on Monday that competing in London in 2012 remained one of Gebrselassie's burning ambitions.

"He has always talked about London 2012," Hermens said. "The moment when he stops international running will come sooner or later but, as many people said, this was not the right moment. London is always in his mind, so he should be there, for sure. This is his last big goal."

Gebrselassie failed to make it past the 16-mile mark in New York, having been troubled by an inflamed right knee, but Hermens said he had already resumed training in the hills above his home in Addis Ababa.