But the Rotorua-based company is still seeking further private investment to deploy a fourth-generation pilot plant at Ecogas.
The iPhone maker is within reach of being the world's first trillion-dollar company.
The investment approval allows the company to complete its testing phase and move into a commercial phase.
Datacom's revenue grew 9.3% to $1.27 billion.
The latest mobile and landline numbers for New Zealand's three largest telcos.