Solid Energy says the global economic slowdown is hitting its international coal sales, and it's not expecting any respite soon.
The publicly-owned coal miner says exports rose a fifth to 2.4 million tonnes for the year to June, while production rose 3% to 4.1 million tonnes.
Solid Energy sells most of its coal to India and China, where its hard coking coal is used in steel making, and its thermal coal is used in power generation plants.
Solid Energy group resources manager Barry Bragg says the global slowdown has hit prices and margins, while the high New Zealand dollar has not helped.
He says hard coke and coal prices are around $US200 - $US210 per tonne now, a drop from around $US300 a tonne 12 months ago.
Mr Bragg says thermal coal was about $US125 a tonne 12 months ago, but is now down to about $US85 per tonne.
He says the price drop combined with a strong New Zealand dollar has been challenging for Solid Energy's margins.
Mr Bragg says there's been a slowdown across the board and Solid Energy is expecting a challenging 12 months.