UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

July 1, 2016

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:    x  Form 20-F     ¨  Form 40-F

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):  ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):  ¨

Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934:    ¨  Yes    x  No

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): n/a

NEWS RELEASE

UPDATE: SAMARCO BRAZIL

On 2 March 2016, BHP Billiton announced that an agreement had been entered into between Samarco Mineração S.A (Samarco), Vale S.A (Vale) and BHP Billiton Brasil LTDA (BHP Billiton Brasil) with the Federal Government of Brazil, the States of Espirito Santo and Minas Gerais and certain other public authorities (Brazilian Authorities) (Framework Agreement).

The Framework Agreement provides for the restoration of the environment and communities affected by the Samarco dam failure on 5 November 2015 and suspension of the civil public claim commenced on 30 November 2015 by the Brazilian Authorities against Samarco, Vale and BHP Billiton Brasil which sought the establishment of a fund of up to BRL20 billion in aggregate for clean-up costs and damages relating to the dam failure.

The Framework Agreement was subject to ratification by the courts in Brazil. On 5 May 2016, the Framework Agreement was ratified by the Federal Court of Appeal in Brasilia.

The Federal Prosecutors’ Office appealed against the ratification of the Framework Agreement. On 30 June 2016, the Superior Court of Justice in Brazil issued an interim order suspending the decision of the Federal Court of Appeal to ratify the Framework Agreement.

The effect of the interim order of the Superior Court of Justice is to reinstate the BRL20 billion public civil claim made by the Brazilian Authorities against Samarco, Vale and BHP Billiton Brasil.

BHP Billiton Brasil intends to appeal the decision of the Superior Court of Justice.

In the meantime, Samarco will continue to support the long-term recovery of the communities and environment affected by the dam failure.

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Further information on BHP Billiton can be found at: bhpbilliton.com

Members of the BHP Billiton Group which is

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.