The collapse of Rio Tinto Ltd. (RTP) and BHP Billiton Ltd.'s (BHP) planned US$116 billion iron ore production joint venture is "purely a commercial matter," Australian Minister for Resources & Energy Martin Ferguson told Dow Jones Newswires Monday, declining further comment.

The planned joint venture, which would have been responsible for around a third of the global iron ore trade, had been facing problems for months as regulators in Germany, the European Union, Japan, South Korea, Taiwan, China and Australia picked over the details of the proposal.

In September, both companies asked the Australian Competition & Consumer Commission, the country's regulatory body, to halt its review of the proposed joint venture so the companies could work out some more details of the proposed agreement.

-By Rachel Pannett, Dow Jones Newswires; 61-2-6208-0901; rachel.pannett@dowjones.com