At the company’s four Western Australian gold mines last month, 45,000 ounces of gold was mined and 33,449oz was poured, compared to 34,302oz mined and 25,337oz poured in March.

Gold in stockpiles, circuit and transit increased to 72,544oz.

Unaudited all-in sustaining costs were $A1010 per ounce, down 13% on the March quarter, against an average realised gold price of $1413/oz for April.

The strong month puts Northern Star on track to exceed its June-quarter guidance of 80,000-90,000oz at AISC of $1100/oz.

For the 2014 financial year, group production is expected to be 180,000-190,000oz gold at AISC of $1100-1150/oz.

Aside from its Paulsens operation, Northern Star acquired the Plutonic mine on February 1 and the Kanowna Belle and Kundana mines on March 1.

Northern Star managing director Bill Beament said the company was already seeing the results of an operational restructure across the new operations.

“These early results show that we are making significant progress in bedding down these assets,” he said.

“We have been able to hit the ground running because we assembled an extensive executive and mine management team before we made the acquisitions.

“This meant that while we had excess capacity for a short time, we were perfectly placed to absorb and restructure these assets immediately after we acquired them.”

Beyond the end of the current financial year, Northern Star is aiming to produce more than 350,000oz per annum at AISC of $1050/oz.

The acquisitions and subsequent production growth will make Northern Star the fifth-biggest gold miner on the Australian Securities Exchange.

Beament has made no secret of the company’s further growth plans, with eventual production rates of 500,000-600,000ozpa targeted.

“Global investors are demanding that gold miners have critical mass and a diversified asset base,” he said.

“These acquisitions ensure we now have these attributes and I am very confident that Northern Star’s well-established commitment to productivity and efficiency will continue to drive value from these new assets.”

Shares in Northern Star dropped 2.2% to $1.095.