Former world number one Ivanovic retires at age 29

By Zoran Milosavljevic BELGRADE (Reuters) - Former French Open champion Ana Ivanovic announced her retirement from tennis at the age of 29 on Wednesday because she no longer feels fit enough to compete at the highest level. Ivanovic became the first Serbian woman to win a grand slam tournament when she beat Russian Dinara Safina in the 2008 French Open final, following in the footsteps of compatriot Novak Djokovic who clinched the Australian Open title the same year. It has been a difficult deci