SYDNEY, Sept 17 (Reuters) - Swedish private-equity firm EQT has ended talks to buy Australia's Iress Ltd for $2.3 billion, sending shares in the financial software company spiralling lower on Friday.

Despite raising its bid three times to gain exclusive due diligence access, EQT said it had decided not to proceed with an offer for one of the main providers of trading and investment software to Australian brokers, advisors, banks and insurers.

"We have not come across any red flags during our due diligence but were not able to sufficiently confirm our investment hypothesis," Thomas Von Koch, EQT's Chairman of Asia-Pacific, said in a joint statement with Iress.

Iress shares fell 10.7% to A$12.08 ($8.83) after Friday's announcement by the two firms. EQT had raised its bid last month to A$15.91 per share, valuing Iress at A$3.2 billion after its two previous offers were rejected.

"Although we expect management's strategy to successfully restart earnings growth, it will take time and we expect shareholders will be increasingly impatient following the failure of the EQT bid," Morningstar analyst Gareth James said.

The Australian company said it remained committed to doubling its net profit after tax by 2025 with potential for further upside, and reaffirmed its full-year 20221 forecast for segment profit of between A$164 million and A$168 million.

It said it had spent about A$4 million to A$5 million before tax in the unsuccessful transaction.

In 2019, EQT also withdrew https://www.reuters.com/article/vocus-ma-eqt-infrastructure-idUSL4N23B25V a A$3.3 billion buyout offer for Australian telco Vocus Group after a due diligence period. The firm was later acquired by a consortium https://www.reuters.com/article/us-vocus-group-m-a-macquarie-idUSKBN2B10BP for A$3.5 billion. ($1 = 1.3710 Australian dollars) (Reporting by Paulina Duran in Sydney and Arundhati Dutta in Bengaluru; Editing by Krishna Chandra Eluri, Anil D'Silva and Alexander Smith)