Any significant changes to the corporate structure of Anglo-Australian miner BHP Billiton Ltd. (NYSE: BHP) would need to be consistent with a "national interest" test under the law, the Australian government said April 11.

Activist shareholder Elliott Advisors on April 10 proposed BHP Billiton scrap its dual-company structure in favor of a primary listing in London and a secondary listing in Sydney.

"A change in the corporate structure and listing arrangement would need to be carefully considered against the provisions of the Foreign Acquisitions and Takeovers Act," a spokeswoman for Australian Treasurer Scott Morrison said April 11.

RELATED: BHP Resists Call To Ditch Eagle Ford Shale, Permian Oil

"If the changes were significant they would need to be consistent with Australia’s national interest test under that Act," she added.

The Australian government in 2001 approved the merger of Melbourne-based BHP and London-based Billiton based on a number of conditions designed to ensure the miner kept close ties to Australia.

BHP Billiton said April 10 the Elliott proposal, which involves replacing the dual-listed company with a single company domiciled in Britain, would require the approval of Australia's Foreign Investment Review Board.

In presentation slides, Elliott said the changes in the listing structure would add $1.50 of value per BHP Billiton share for the holders of London-listed shares but take away $1 in value from the holders of the Australian-listed shares.

The bulk of Elliott's BHP Billiton shareholding is in the U.K.-listed arm, in which it holds a stake of 4.1%. It has rights to acquire an interest of up to 0.4 percent in the Australian-listed arm.

Elliott also proposed that BHP Billiton split off its U.S. oil and gas division, a move the company has rejected previously.