UPDATE 1-Japan Properst says filed for bankruptcy protection

* Says debt exceeds $597 million

* Aims to keep shares listed on the Jasdaq

* Marks third corporate failure in Japan this year

(Updates with more details)

TOKYO, May 14 (Reuters) - Japanese real estate developer Properst Co 3236.Q said on Friday it had filed for bankruptcy protection with 55.4 billion yen ($597 million) in debt after a drastic restructuring failed to offset weak condominium sales.

The announcement came as Japan’s property market starts to recover after a prolonged slump in prices and demand in the wake of the global financial crisis.

To ride out of the country’s property market woes, the Jasdaq-listed Properst had implemented restructuring steps including slashing the jobs of half its staff, but these failed to revamp its business.

The company, which will meet press at 0300 GMT, said it aims to turnaround its business while keeping its shares listed under the Jasdaq’s exceptional listing rule.

The move marks the third failure of firms listed in Japan this year, according to Tokyo Shoko Research. (Reporting by Mariko Katsumura; Editing by Joseph Radford)