Changes sourcing to Elliott, recasts throughout

June 1 (Reuters) - Elliott Investment Management on Monday disclosed an over A$1 billion ($714.60 million) stake in Northern Star Resources NST.AX, calling for the Sydney-listed miner to appoint an external CEO and launch a strategic review including a sale.

The U.S.-based activist investor cited Northern Star's underperformance versus peers, "repeated operational missteps", seven outlook misses in four years, and "deeply inadequate disclosures compared to global senior peers".

The Australian Financial Review first reported the stake on Monday, saying the 4% holding would place Elliott among the miner's top five shareholders.

Northern Star did not immediately respond to a Reuters request for comment.

The miner's shares have fallen over 31% this year, while peers Evolution Mining EVN.AX and Perseus Mining PRU.AX are down 2% and 8%, respectively.

The gold producer has faced operational setbacks at its flagship Kalgoorlie Consolidated Gold Mines, but launched an A$500 million buyback in April, saying the current share prices "do not fully reflect the quality and future potential of our assets".

Last month, managing director Stuart Tonkin also announced his resignation after 13 years, effective the first quarter of fiscal 2027.

In its presentation, Elliott, which manages nearly $79.8 billion in assets, said Northern Star should also refresh its board with directors who have gold mining operational expertise.

Elliott said Northern Star's valuation materially understates the quality of its underlying assets, describing the Kalgoorlie mine as having the potential to be one of the world's largest gold mines and the Hemi project as among the most attractive greenfield gold projects in the developed world.

"Northern Star's recent pattern of operational missteps, cost overruns and inconsistent strategic direction demands urgent action," Elliott added.

($1 = 1.3994 Australian dollars)