KUALA LUMPUR, May 29 (Reuters) - Malaysia's state fund 1Malaysia Development (1MDB) TERRN.UL has signed a deal securing $1 billion in funding from Abu Dhabi's International Petroleum Investment Company (IPIC) INPTV.UL and its Aabar Investments unit ahead of a June 4 deadline to repay a loan to an international bank syndicate.

Malaysia's finance ministry said in a statement on Friday that the amount will be used to repay a $975 million loan to the syndicate in advance of the due date. Securing the funds marks a major milestone in plans to restructure loss-making 1MDB.

"This agreement marks a significant step towards reducing 1MDB's overall debt levels, and is a crucial part of the rationalisation plan I presented to cabinet earlier (Friday)," deputy finance minister Ahmad Husni Hanadzlah said in a statement.

The government official said the ministry expects plans to restructure 1MDB to be implemented "in full by early next year".

(Reporting by Yantoultra Ngui; Editing by Kenneth Maxwell) ((yantoultra.ngui@thomsonreuters.com; +60323338036; Reuters Messaging: yantoultra.ngui.thomsonreuters.com@reuters.net))