UPDATE 2.40pm: Northern Star Resources is officially the second-biggest ASX-listed gold miner after completing its acquisition of the Jundee mine from US giant Newmont.
The $82.5 million deal will propel Northern Star towards production rates of between 550,000 and 600,000 ounces per annum.
There is still daylight between Northern Star and Australia's biggest gold producer,
Newcrest, which forecasts between 2.2 and 2.4 million ounces this financial year.
Northern Star's Jundee acquisition included $10 million of shares for millionaire prospector Mark Creasy, who waived a pre-emptive right to buy the mine near Wiluna.
The deal follows a buying frenzy by Northern Star, which this year spent $100 million to wrest control of Canadian giant Barrick Gold's Kanowna and Plutonic operations.
Northern Star managing director Bill Beament said there is "significant potential" to grow Jundee's resources through near-mine exploration.
Jundee produced 63,000oz in the March quarter at all-in sustaining costs of $US841/oz.
"The Jundee acquisition is entirely consistent with our objective of being a major Australian gold mining company for global investors," he said."We now have the scale, the asset diversity, the cost base and the growth potential demanded by leading investment institutions around the world."
Following the completion of the Jundee acquisition, Northern Star has $80 million cash on hand and has drawn down $70 million of a $100 million credit facility.
Northern Star shares closed up half a cent at $1.315.