BERNE, Switzerland, Oct 11 (Reuters) Former world number one Martina Hingis has called an early end to her 2007 season after failing to recover from a string of injuries and health problems.
Hingis, 27, announced her decision via the organisers of the WTA tournament in her home city of Zurich, where she was due to play next week.
''I'm very disappointed that I have to withdraw from the Zurich Open,'' Hingis was quoted as saying in today's statement.
''I've done everything I can to be able to compete, but since Key Biscayne I've had problems with my hip which are stopping me from playing any more tournaments this year and even from practising properly.'' Hingis' anticipated withdrawal from the event has led to Swiss media speculation about a possible retirement.
In today's statement Hingis said she would take ''as much time as it needs to get fully fit again''.
Hingis has already announced her retirement from professional tennis once, hanging up her racket in 2003 after failing to overcome lingering ankle injuries.
She made a part-time return to the sport in 2005 before launching a full comeback in 2006 -- winning tournaments in Rome and Calcutta to finish the year as world number seven.
She added a further title in 2007 with victory in Tokyo before the onset of her latest injury troubles.
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