Australian company De Grey Mining has surrendered its permit to carry out low-impact exploration on a 6500 hectare block in the Russell State Forest.
The company still holds two active permits to investigate mining copper, gold, silver, lead and zinc on blocks in the Puhipuhi hills.
A change of conditions has been applied for and is pending on one of those permits, number 51985.
De Grey's permit 55058 for the "north Puhipuhi" block in the Russell forest was due to expire in 2018.
However, the company applied to drop that permit in October and was given approval by the New Zealand Petroleum and Minerals (NZP&M, formerly Crown Minerals) on December 17. De Grey Mining declined to comment on why it dropped the 55058 permit, what changes the company is awaiting confirmation of on number 51985, or whether NZP&M-imposed timelines are behind the move.