The SPP is underwritten up to $750,000 by Pattersons Securities, which is also acting as lead manager to the offer.
Under the SPP shareholders can buy up to $15,000 worth of new shares without incurring brokerage or other transaction costs.
The issue price is to be determined at the issue date of new shares under the plan based on a 20% discount to the volume weighted average price of Niuminco's shares traded on the Australian Securities Exchange during the five days immediately prior to the issue date and at no less than A0.4c. At the moment Niuminco shares are trading at A0.6c.
The increased exploration will be focused on drilling campaigns at both May River and Bolobip in Papua New Guinea.
Niuminco has three projects in PNG: Edie Creek, which is an operating mine, and the exploration plays May River and Bolobip.
Edie Creek, about 210km northwest of Port Moresby and 120km south of Lae, turned out 317 ounces of gold in the June quarter.
Niuminco managing director Tracey Lake said the company wanted to lift its ore processing throughput to more than 40t per day and increasing gold production towards a targeted 200 ounces at Edie Creek.
"Additionally we can now accelerate our exploration programs at Bolobip and May River and funds raised will be used to drill test these exciting targets," he said.