A senior executive of one of the world's biggest miners is not ruling out more changes to the mining profits tax.

Mr Peter Freyberg CEO of Xstrata Coal thinks the debate is over for now but he has warned tax reform is one of the biggest challenges facing the mining industry.

Mr Freyberg said that multinational companies could send their investments offshore if they did not like Australia's tax policies. Government needs to understand how decisions are made by industry and what impact policy decisions can have on investor confidence and perceptions of sovereign risk.

He said that it was not a threat to the incoming government over the mining tax. It's not a threat. It's a statement of fact. We look at investing in the most competitive region we can to maximize returns for our shareholders. If policy makes Australia less competitive, then we'll see that investment move elsewhere.

Mr Freyberg was speaking before the announcement by the two regional independent politicians, Mr Tony Windsor and Mr Rob Oakeshott that they would support a minority Labor government.

Xstrata, Rio Tinto and BHP Billiton negotiated a reduction in the mining tax with PM Ms Julia Gillard from 40% to 30% of profits for the iron ore and coal industry.

Mr Don Argus the former chairman of BHP Billiton is advising the government on the implementation of the tax. We know there are parties out there that would like to see it done differently. We are quite satisfied with the outcome in terms of the discussion we had in Canberra.

(Sourced from ABC.Net)