Todd Energy is seeking $274 million in damages from its partners in the Pohokura gas field near Taranaki.
Todd Energy claims Shell and OMV, its partners in the field, are producing about 20% less gas each year than they can, and this substantially reduces competition in the gas market, and holds prices artificially high.
Shell and OMV deny the accusations.
The dispute heads to court on Monday. Judge Robert Dobson will preside over the case. He will sit with an economist lay member, Professor Martin Richardson, from Australia.
The case is being heard in the High Court at Wellington and is expected to take up to eight weeks.
Pohokura is the most important source of gas for New Zealand since the wind-down of the Maui field was announced.
Both it and Maui have been subject to repeated lawsuits involving Todd and its partners.
