MELBOURNE (Reuters) -BHP's head of Australia, Geraldine Slattery, said on Wednesday the country must speed up environmental approvals and boost access to cheap power if it hopes to compete for mining investment capital with other nations.

The comments from the world's biggest listed miner underscore rising competition for capital with nations like the United States that are ramping up mining friendly policies to spur development of an alternative supply chain to dominant producer China.

Slattery outlined what she said Australia needed "to compete in the global market".

"This is not a small matter, it's a linchpin to make the resources and many other sectors more productive," Slattery said, in reference to permitting timeframes, in remarks prepared for a conference in Western Australia.

BHP CEO Mike Henry said this week the company was considering reopening old mines in Arizona as a result of the U.S. administration's "breathtaking" shift to build up the mining industry, in an interview with the Financial Times.

Australia is reaching the final stages in negotiations to reform its environmental laws. New legislation is expected to be introduced to parliament in its final sitting fortnight of the year, local media have reported.

Slattery, who has been at BHP for three decades and previously led its petroleum business, has been mooted as the front runner for BHP's top job. Henry has been expected to step down by the middle of next year after a typical six-year tenure.

"Australia's labour productivity growth is now at a sixty-year low. This is not some isolated economic statistic. It's a trend that poses challenges, not only for attracting future investment, but also for sustaining the higher standards of living that productivity enables," she said.

Nevertheless, BHP this month earmarked more than A$840 million ($555.16 million) for its Olympic Dam copper operations in South Australia as the miner prepares to make an investment decision by mid-2027 to double output from the state.

Other priorities Slattery listed were for Australia to cut taxes to be more competitive with other developed nations, improve workforce training and embrace automation and artificial intelligence, which she said was core to addressing the country's productivity challenges.