KEY POINTS:
Vodafone is launching a legal challenge against the Commerce Commission about costs it will incur meeting the Telecommunications Service Obligation (TSO).
The phone company is set to pay Telecom about $20 million for the 2005/2006 year for its part of a subsidy towards the provision of free local calling.
Vodafone is appealing against an aspect of the model used by the commission to calculate TSO costs. The case begins in the High Court at Wellington on Monday.
