(Recasts first paragraph, adds details throughout) Aug 19...

(Recasts first paragraph, adds details throughout)

Aug 19 (Reuters) - Coal producer Yancoal Australia (YAL) reported a slump in its first-half profit on Monday and refrained from declaring an interim dividend, hurt by a drop in its underlying coal prices.

The firm said its average realised coal price for the half year was A$176 per tonne, a 37% drop from a year earlier.

Yancoal said the high-ash thermal coal market weakened slightly towards the end of the first half as higher rainfall in China boosted hydropower generation, curbing demand for thermal coal.

Thermal coal is a widely used ingredient for electricity generation.

Lower demand from top consumer China also hurt sales of the company's metallurgical coal, used in the production of steel.

The coal miner did not declare an interim dividend for the period, compared with 37 Australian cents apiece a year ago.

The company logged a profit after tax of A$420 million ($281 million) for the first half, compared with A$973 million a year ago.

($1 = 1.4950 Australian dollars)