A drop in coal prices and a high kiwi have forced Solid Energy to cut 25 percent of its staff, but it is unclear whether the global coal slump means the state-owned enterprise is selling less coal.

Its latest quarterly report shows coal sales were down to just more than 1 million tonnes, compared with 1.12 million tonnes in the June and March quarters and 1.21 million tonnes in the three months to December 2011.

However, compared with the September 2011 quarter, export numbers were unchanged.

Solid's September 2011 quarter sales were inflated by an earthquake-delayed shipment of 149,000 tonnes.

When that is stripped out, the difference between the September 2011-12 quarters is a 1 per cent drop, but left in it makes for a 25 per cent decrease.

The company exported 434,000 tonnes of coal in the September quarter, which is about 170,000 tonnes fewer than the previous 2012 quarters.

Compared with the quarter ended December 2011, there were almost 200,000 fewer tonnes exported.

There are similar up and downs in previous quarterly reports during the past two years.

Domestic sales increased 6 per cent on September 2011, with 572,000 tonnes sold.

The state-owned miner dug up 988,000 tonnes.

Stockton mine, in northern Buller, performed strongly to offset a drop to negligible levels at Spring Creek, near Greymouth.

Solid Energy is axing one in four of its staff because of plummeting coal prices.

- © Fairfax NZ News