Products Alternative Fuels Natural Gas Corporation Product or Service: Natural Gas Corporation (NGC) is one of New Zealand's leading gas transmission, gas distribution, gas wholesaling, electricity generation and energy retailing companies. Postal Address: PO Box 17015, Greenlane, Auckland Phone: 09 520 8234 E-mail: david.mawer@natgas.co.nz Web-site: www.natgas.co.nz