Underlying profit after tax jumped 15% to A$39.9 million, while statutory profit after tax was down 3% to $37.5 million.

Underlying EBITDA rose 17% to $151 million, while the EBITDA margin increased from 36% to 42%.

Cashflow from operating activities was up 45% to $94 million.

St Barbara declared a fully franked interim dividend of 4c per share, in line with the previous corresponding period.

The dividend represents $173 per ounce of gold produced and a dividend yield of 1.7%.

St Barbara managing director Craig Jetson said the first half result was pleasing after operational disappointments in the first quarter, including a fall of ground at Gwalia in Western Australia.

The company closed the half with cash of $119 million and debt of $101 million.

Jetson told investors the company remained in a strong position to be able to advance its growth projects.

The feasibility study into the Simberi sulphide expansion in Papua New Guinea is due later this quarter, with a final investment decision expected "shortly after".

Jetson said based on the information he'd seen, he was excited about the project.

At Gwalia, a broader Leonora province plan is due late this quarter or early next quarter.

"I'm quite optimistic with how we're building the strategy for Gwalia," Jetson said.

In Canada, environmental impact statements will be submitted for the Beaver Dam project.

Shares in St Barbara fell 3.7% to $2.215, in line with falls in the gold sector.