HONG KONG, June 25 (Reuters) - Shimao Group has sweetened its offshore debt restructuring terms to garner support from creditors, said three sources, as the Chinese property developer scrambles to fend off a liquidation petition filed in a Hong Kong court.

Shimao will on Wednesday face its first court hearing into the liquidation petition filed by state-owned lender China Construction Bank (Asia) over unpaid loans of HK$1.58 billion ($201.75 million).

The sweetened offer from Shimao comes after its creditors strongly opposed a restructuring plan it first laid out in March after having defaulted on its $11.5 billion offshore debt in 2022, said the sources familiar with the matter.

In its revised proposal, Shimao has offered "mildly" improved terms including an increase in the minimum cash creditors will be able to collect, one of the sources said, without providing further details.

The source added Shimao and some of its creditors were also negotiating other terms of the restructuring, including its offer of exchanging debt for mandatory convertible bonds.

The sources declined to be named as they were not authorised to speak to media.

Shimao did not respond to request for comment.

Sources previously told Reuters that creditors opposed the March terms because of the size of the losses involved and the lack of upfront payments if the deal was approved.

A growing number of Chinese developers in default are working on debt restructuring plans after failing to meet their offshore debt repayment obligations since 2021, when a stifling liquidity crisis hit the economically crucial property sector.

Some of those negotiations have continued for a long time due to disagreement between the developers and their creditors over the terms of the restructuring plans amid a worsening outlook for the Chinese property sector.

China's new home prices fell at the fastest pace in more than 9-1/2 years in May, official data showed last week, with the sector struggling to find a bottom despite Beijing's efforts to rein in oversupply and support debt-laden developers.

Only a handful of the dozens of major developers that have been in various stages of their debt restructuring plans have been successful in getting the proposals approved by creditors.

Shimao's latest 1.1% early consent fee deadline - which it has already extended twice - to give creditors an incentive to support the restructuring plan expires on Friday. It has not provided details of the support to date.

The developer needs approval from creditors who collectively hold more than 75% of its offshore debt to implement the restructuring proposal and avert a potential liquidation court order. (Reporting by Xie Yu and Clare Jim; Additional reporting by Scott Murdoch in Sydney; Editing by Sumeet Chatterjee and Jamie Freed)