BHP Billiton's contract coking coal price for shipments to Japan has been cut by almost 25 per cent to $US170 a tonne as demand in the region falters, according to a closely watched industry news service.

The lower price will apply for the December quarter for shipments of coal from Queensland to major Japanese steelmakers, according to the Tex Report from Tokyo.

The spot price for price for so-called "hard" coking coal, which is the top grade product, has fallen to about $US150 a tonne, according to the report, with a recent offer put forward at $US140 a tonne, the daily newsletter reported.

The report cited weak demand in China, coupled with shipments from Mozambique as placing coking coal prices under pressure.

In the wake of extensive flooding in Queensland, contract hard coking coal prices topped $US330 a tonne for a time in 2010, up from around $US105 a tonne prior to the supply disruptions, but have fallen subsequently.

"There is a feeling the price reduction has been rather restrained if the current market for coking coal is taken into consideration," the newsletter noted.