SYDNEY (Reuters) - Activist shareholder Elliott Management said it has deep concerns over a proposal by BHP to enter the currently over-supplied fertilizer market, reiterating its call for change at the mining giant.

FILE PHOTO: Australian mining company BHP's new corporate logo, released to Reuters from their Melbourne, Australia, headquarters May 15, 2017. BHP/Handout via REUTERS/File Photo

BHP has signaled it may push ahead with its long-dormant Jansen potash mine in Canada in a counter-cyclical play to capture part of what it sees as a $50 billion-a-year market by the mid 2040s.

Jansen is already under construction but requires BHP’s board to approve another $4.7 billion to bring the mine into production.

New York-based Elliott, which has urged BHP to split off its oil business, scrap its dual listing and return more cash to shareholders, said it shared concerns raised by shareholders and analysts that expanding into potash could be a strategic misstep.

“BHP is now arguing that it should spend billions of dollars of shareholder money to diversify into potash,” an Elliott spokesman said in an email to Reuters.

“This sounds alarmingly familiar and comes as the company proclaims the dubious strategy of thinking big – a concept that has been disastrous for BHP shareholders,” he said, referring to a recent advertising slogan adopted by BHP.

BHP declined to comment on Elliott’s remarks.

The global miner, which currently focuses on iron ore, copper, coal and petroleum products, has released an investment paper justifying the need for more potash to help feed a rising global population on limited arable land.

Chief Executive Andrew Mackenzie said in May that development of the Jansen mine “could be something that we seek board approval of as early as June next year, with possible first production in 2023.”

Elliott holds about 4 percent of BHP’s stock.

It has kept up its criticism of the miner since April when it released a list of changes it wants the company to make, including an exit from U.S. shale oil and gas, where BHP has invested more than $20 billion over six years and taken impairments of $13.1 billion.

Outgoing BHP Chairman Jac Nasser said last month that in hindsight that investment was a mistake.