Switzerland's top figure skater Stéphane Lambiel has split from his long-time coach after a disappointing performance at the world championships earlier this year.
He announced on Friday that he would start working under United States-based trainer and former Olympic gold winner Viktor Petrenko.
Lambiel said it had been a difficult decision to leave his coach of 13 years, Peter Grütter, but he was in need of a "new challenge".
"I owe an enormous amount to Peter Grütter. We part on good terms and remain good friends," he said.
The two-time world champion and Olympic silver medallist only managed fifth place in the last World Figure Skating Championships in Gothenburg, Sweden.
He will now start working towards the 2010 Olympic Games under Petrenko, a 38-year-old Ukrainian, and Petrenko's former coach Galina Smijewska.