Port of Tauranga has reported strong rises in forestry-related exports and in imports of grain and dairy food supplements.

Telecom shares sank to new a low on the NZ sharemarket today, while rises in Fletcher Building, Contact Energy and other leaders helped carry the market higher.

Port of Tauranga, New Zealand's biggest export port, has posted a 2 per cent gain in first-half profit by reining in costs as freight volumes fell, eroding revenue.