Norwegian oil firm Statoil has been granted a permit to explore a further 1670sq km of seabed off Northland's west coast.
The new block adjoins a 9800sq km area in the Reinga Basin, about 100km off Ninety Mile Beach, that the state-owned oil giant is already exploring. The two areas will be explored together.
Statoil's expanded area is one of 15 new oil and gas exploration permits announced by Energy and Resources Minister Simon Bridges as part of Block Offer 2014. It is the only new permit in Northland.
The news, which comes just days after the Stopstatoil Festival at Ahipara, has been welcomed by Northland MP Mike Sabin but decried by environmental groups.
Mr Sabin said the Northland-Reinga basin totalled 54,000sq km and was one of the country's most promising frontier basins.