BERLIN: 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.

"There is no other way to say it. I have decided to retire from professional tennis. It has been a difficult decision but there is so much to celebrate," Belgrade-born Ivanovic said on Facebook.

Ivanovic, the world number 63, married former Germany soccer international Bastian Schweinsteiger this year.

"I am so excited about what comes next. I will become an ambassador of sport and healthy life and will also explore opportunities in business, beauty and fashion, among other endeavors," she said.

"Beyond that, who knows. All I can say is that I have lived my dreams and really hope to have helped others do so as well."