OceanaGold is planning to spend at least US$9 million ($11.9 million) on exploration in this country.

The company said yesterday its proven and probable reserves in New Zealand had risen to 2.15 million ounces of gold at the end of December.

That was up from 1.92 million ounces a year earlier, and after the company sold 268,000 ounces of gold from its New Zealand operations during last year.

OceanaGold said it had expanded its mineral reserves for the second year in a row.

Chief executive Mick Wilkes said two years ago the company had a reported average reserve life of just 3.5 years at its New Zealand operations.

Now, the open cut operations were demonstrating seven to eight years of mine life with a respectable amount of reserves still growing at the Frasers underground operation and "tremendous" blue sky opportunities at Reefton.

"This transformation will underpin the solid operational base in New Zealand for some years to come as we pursue other growth opportunities," Mr Wilkes said.

"We are spending at least US$9 million this year on exploration in New Zealand."