Tennis-Switzerland's Martina Hingis

Oct 26 (Reuters) - Factbox on Swiss Martina Hingis who announced on Thursday her retirement from tennis at the end of this week's WTA Finals.

*A Swiss citizen born in Kosice, Czechoslovakia (now in Slovakia) on Sept. 30, 1980 to tennis players Melanie Molitorova and Karol Hingis.

*Became the youngest Wimbledon champion aged 15 by winning the women's doubles title with Helena Sukova in 1996.

*Became the youngest grand slam singles champion in the 20th century by winning the Australian Open in 1997, aged 16. Also won Wimbledon and U.S. Open in the same year, becoming the first player since Steffi Graf in 1993 to reach finals of all four grand slams.

*In 1997 became the youngest world number one and spent 80 consecutive weeks at the top before ankle injury cost her the top ranking.

*Finished 2000 as world number one after claiming nine titles.

*She lost her number one ranking in 2001 after tearing ankle ligaments.

*Pulled out of German and Italian Opens and missed Wimbledon due to injury.

*Announced in October, 2002 she would take an indefinite break from tennis.

*Made a comeback at the Australian Open in 2006, reaching the quarter-finals before climbing to sixth in the world rankings.

*In November 2007, Hingis said she was under investigation after testing positive for cocaine. She announced her retirement for the second time but denied she had ever taken performance-enhancing drugs.

*Hingis was inducted into the International Tennis Hall of Fame in 2013 and announced that she was coming out of retirement to play a doubles tournament in California.

*Hingis paired with India's Leander Paes to win the mixed doubles crown at the 2015 Australian Open, her first grand slam title since capturing the mixed doubles in Melbourne in 2006.

*She won the women's doubles title at Wimbledon with India's Sania Mirza before clinching the mixed doubles crown with Paes the next day.

*She also claimed the women's doubles and mixed doubles titles at the U.S. Open to finish with five grand slam trophies in 2015.

*Completed her mixed doubles career grand slam with first title at Roland Garros alongside Paes.

*Played doubles with compatriot Timea Bacsinszky and won the silver medal at the 2016 Rio Olympics.

*Won the mixed doubles title with Britain's Jamie Murray at Wimbledon and the U.S. Open in 2017. She also lifted the doubles title at Flushing Meadows with Taiwan's Chan Yung-jan.

*Finished her career with 25 grand slam titles in singles and doubles. (Compiled by Hardik Vyas in Bengaluru, editing by Ed Osmond)