The investment bank noted that Glencore’s announcement to cut 15Mtpa in Australia and potentially 5Mtpa in South Africa provided some initial support to coal pricing.

However, it has since concluded that China’s glut of coal production, with a total output quadrupling the total seaborne coal export market, is “the real culprit behind low thermal coal prices”

The bank said output cuts outside China could be easily offset by a corresponding decline in Chinese thermal coal import volumes.

“The actions of seaborne producers will be secondary to Chinese domestic market dynamics as long as China is a large importer,” Goldman said in a report last week.

It forecasted China’s share of seaborne coal market demand to fall from 17% last year to 12% this year, before slipping into single digits from 2016 and beyond.

“China may eventually cease to be a significant market for seaborne coal, and the price ceiling currently set by cheap domestic coal would gradually disappear," Goldman said.

China has been implementing various coal quality restrictions and coal taxation measures since October. These measures were estimated to cut 10 million tonnes of annual global seaborne exports alone, Macquarie Wealth Management said earlier this year.

Other brokers suspected that Glencore’s 15Mtpa cut in Australian production was designed to boost prices during annual contract negotiations with Japanese utilities.

Rio Tinto’s $US67.80 per tonne settlement with a Japanese utility last week was short of some expectations of a $70/t benchmark price.

However it was still well north of Newcastle spot thermal coal prices which traded as low as $55.60/t for April delivery.