Coronado Coal says higher costs, taxes and bad weather are squeezing its mining operations, pushing profits almost 80 per cent lower over the last year.

A 21.7 per cent rise in the cost of producing each tonne of coal and a taxes and royalties bill of $US630 million ($965 million) drove down the miner’s full year statutory profit to $US156.1 million on Tuesday, compared to $US771.7 million a year earlier.