In a prospectus lodged on Monday, Healthscope said it would raise total proceeds under the offer from A$2.25 billion to A$2.57 billion, assuming the final price is within its indicative price range of between A$1.76 and A$2.29.

The planned listing of Australia's second-largest private hospital operator underlines the growing appeal of the healthcare sector in Australia, where spending is growing more than 8 percent annually, according to Healthscope.

The newly listed company will have a market valuation of between A$3.33 billion and A$3.81 billion. Healthscope will retain at least 25 percent of the shares on issue, but reserves the right to retain up to 40 percent.

Managing Director Robert Cooke said the company is planning to invest around A$274 million between 2015 and 2017 building new private hospitals.

The number of Australians with private health insurance - the biggest driver of private hospital revenue - has risen from 9.8 million to 11 million since 2009 - just under half the population - as the state pays a 30 percent rebate on private health insurance premiums.

TPG and Carlyle bought Healthscope, which also provides pathology services in Australia, New Zealand, Malaysia and Singapore, in 2010 for A$1.99 billion ($1.73 billion at the time).

Part of the IPO proceeds will be used to pay down debt, the company said. The company had net debt of A$865.5 million at Dec. 31, 2013.

The proposed listing would be the largest in Australia since rail freight company QR National Ltd, now known as Aurizon Holdings Ltd (>> Aurizon Holdings Ltd), raised $4.4 billion in November 2010, according to Thomson Reuters data.

Healthscope plans to announce the final price on July 25, before conditional trading begins on July 28.

(Reporting by Jane Wardell; Editing by Stephen Coates)