International trade and investment law

The Office of International Law works closely with the Department of Foreign Affairs and Trade (DFAT) in negotiating international trade agreements. It is also responsible for providing advice to government on compliance with its international trade obligations. In addition to general treaty drafting, it has a particular expertise in areas such as:

• dispute settlement
• investment
• telecommunications
• intellectual property.

International trade agreements are negotiated at any one of the following 3 levels:

• multilateral level, under the umbrella of the World Trade Organization
• regional level, such as Asia Pacific Economic Cooperation (APEC)
• bilateral level, such as free trade and investment agreements with key trading partners.

Find the Australian Government's Free Trade Agreements and information about Australia's trade policy on the Department of Foreign Affairs and Trade website.

Investor-state dispute settlement

The Office of International Law is responsible for managing investor-state dispute settlement (ISDS) cases.

For more information on Australia’s position on ISDS provisions, visit the Department of Foreign Affairs and Trade website.

Previous ISDS claims

In 2015, Australia successfully defended an ISDS claim brought by Phillip Morris Asia challenging Australia’s introduction of plain packaging tobacco legislation. On 18 December 2015, the Tribunal found it had no jurisdiction to hear the claim.

In 2025, Australia successfully defended an ISDS claim brought by Zeph Investments, a Singaporean entity ultimately owned by Mr Clive Palmer. On 26 September 2025, the Tribunal found that it had no jurisdiction to hear the claim. Subsequently, Zeph made 2 applications to the Federal Supreme Court of Switzerland. The first application, filed on 22 October 2025, was to set aside the Tribunal’s decision. The second application, filed on 9 December 2025, requested a ‘revision’ of the Tribunal’s decision. The Federal Supreme Court of Switzerland rejected both applications, upholding the Tribunal’s decision.

Find out more about the Zeph Investments Pte Ltd v The Commonwealth of Australia (I) on the Permanent Court of Arbitration website.

Current ISDS claims

Currently, Australia is defending 3 additional ISDS claims brought by Zeph Investments. The parties have agreed to temporarily suspend proceedings in these arbitrations.

Zeph Investments Pte Ltd v The Commonwealth of Australia (II)

This claim (PCA Case No 2023-67) relates to certain mineral exploration permits held by Mr Palmer’s Australian company, Waratah Coal Pty Ltd, in the Galilee Basin of Queensland. Zeph seeks damages of approximately A$41 billion in this claim.

Find out more about Zeph Investments Pte Ltd v The Commonwealth of Australia (II) on the Permanent Court of Arbitration website.

Zeph Investments Pte Ltd v The Commonwealth of Australia (III)

This claim (PCA Case No 2024-23) relates to a Queensland Land Court recommendation and subsequent decisions of the Queensland Government to refuse an application by Waratah Coal for a mining lease and environmental authority for activities in Queensland’s Galilee Basin. Zeph seeks damages of approximately A$69 billion in this claim.

Find out more about Zeph Investments Pte Ltd v The Commonwealth of Australia (III) on the Permanent Court of Arbitration website.

Zeph Investments Pte Ltd v The Commonwealth of Australia (IV)

This claim (PCA Case No 2024-48) relates to decisions of the Queensland Government to refuse environmental authority and development approval for a proposed coal-fired power plant as part of Waratah Coal’s Galilee Coal Project. Zeph has estimated the value of the project at approximately A$10.5 billion.

Find out more about Zeph Investments Pte Ltd v The Commonwealth of Australia (IV) on the Permanent Court of Arbitration website.

Ye Cheng and others v. Australia (ICSID Case No. ARB/26/18)

On 8 April 2026, entities associated with the Landbridge Group (Landbridge) filed a request for arbitration against Australia concerning the Port of Darwin. Landbridge raised this claim under Chapter 9 of the China Australia Free Trade Agreement and the Convention on the Settlement of Investment Disputes Between States and Nationals of Other States.