TPG Telecom's first-half profit has slumped 76.5 per cent to $46.9 million after its decision to halt the rollout of its planned mobile network resulted in a $227.4 million impairment.

TPG Telecom's first-half profit has slumped 76.5 per cent to $46.9 million after its decision to halt the rollout of its planned mobile network resulted in a $227.4 million impairment.