Rome, December 12 - Federica Pellegrini made a successful return to competition after her disappointing London Olympics when she helped the Italian women's team reach the final of the 4x200m freestyle relay at the short-course swimming world championships in Istanbul on Wednesday. Pellegrini and her teammates qualified by finishing third in their heat with a time of seven minutes 47.95 seconds. The 24-year-old was one of Italy's big gold medal hopes for the London Olympics but she could do no better than fifth in the 200m and 400m freestyle. It was a massive disappointment for an athlete who is the double world champion and world record holder in both events and went to the Games as the reigning Olympic champion in the 200m. Pellegrini is having a sort of 12-month sabbatical after the Olympics and she is limiting the amount of competition she does and the intensity of her training. She is only taking part in the 4x200m freestyle and 4x100m medley relay events in Istanbul. The 4x200m relay final takes place later on Wednesday.