Asia gobbles up some 70 percent of all coal used for power generation, and the unprecedented demise of its futures market poses significant risks for utilities in particular.

With coal prices rising sharply this year, power generators would usually hedge or protect themselves by taking positions in related derivatives markets.

"With Asia's futures pretty much gone, that greatly increases our risk for supplies in that region. It may mean that we source less from there going forward," said a risk manager with a big European utility, declining to be named as he was not authorised to speak publicly about company risk.

Data from several exchanges shows that since its heyday in 2015, Asia coal futures trading activity has declined by over 90 percent.

Two senior coal brokers and six senior traders at merchant houses, utilities and miners spoken to by Reuters pointed to the shrinking role of Singapore-listed commodity merchant Noble Group (>> Noble Group Limited) as the single most important factor in the decline of Asian coal futures volumes.

Noble has sold-off assets and slashed trading operations following allegations from Iceberg Research in 2015 that it had overstated its assets by billions of dollars, sending its share price tumbling.

"Noble is a massive loss to the market. Its troubles seriously dented liquidity," one merchant trader said.

Noble declined to comment for this article, but said in a letter to Singapore Exchange in May "very thin trading liquidity" in hedging instruments had contributed to its first quarter losses.

GLENCORE DOMINANCE

Many traders also see a link between declining Asian coal futures and the growing dominance of a single company in supplying physical Asian coal.

Swiss-based, London-listed Glencore (>> Glencore) is the world's biggest producer of thermal coal, exporting well over 50 million tonnes from Australia alone in 2016, a quarter of the country's shipments. Physical Newcastle coal prices, which act as Asia's key futures benchmark, have jumped from around $70 to over $100 per tonne this year.

Glencore, which owns a dozen thermal coal mines in Australia, declined to comment. But market participants say the firm is not as active in coal futures trading as many of its peers, instead preferring bilateral supply deals with customers.

"Doubts over deliberate intervention on the supply side for Australian coal linger, which kills any enthusiasm to trade the (financial) product," said Georgi Slavov, head of research at commodity brokerage Marex Spectron.

Glencore's control and knowledge of actual coal output in Australia and the influence this has on derivatives contracts means it is difficult for outsiders to predict price movements, scaring off traders.

"If you don't know what Glencore's mines are up to, it's very hard to trade Australian coal futures," said one trader with a large European utility. "It's not Glencore's wrongdoing, just the way it is."

Glencore has previously said it is as vulnerable as any other market participant to commodity price swings, and in the past has also used derivatives to hedge its own production.

STEEP DECLINE

The decline in Asian coal futures volumes stands in stark contrast to booming oil and natural gas futures.

The amount traded in front-month Australian coal futures on the Intercontinental Exchange (>> Intercontinental Exchange Inc) has collapsed from a high of over 1.6 million tonnes in September 2014 to under 290,000 tonnes this September.

Data from rival CME Group (>> CME Group Inc) shows that open interest, which describes the number of open positions, of its Asian coal futures as fallen from around 2.7 million tonnes in early 2015 to just 65,000 in August this year, with Indonesian and Chinese futures totally vanishing.

"In that sort of environment, utilities stop hedging. It's too risky," said a senior coal trader with a major commodity merchant, requesting anonymity.

Major European utilities that source international coal include Germany's RWE (>> RWE), Uniper (>> Uniper SE) and ENBW (>> Enbw Energie Baden Wuerttemberg AG), Italy's ENEL (>> Enel), Sweden's Vattenfall, as well as Switzerland's Axpo Holding.

"All coal derivatives markets have shrunken this year… as a result of lower options trading, and due to some counter parties that have become less active," said Joachim Hall, cross commodity trader at RWE Supply & Trading, the trading arm of Germany's biggest power supplier.

"Europe's API2 (coal futures market) remains liquid, but it does not move in parallel with physical coal we buy in Asia," Hall said.

VOLUMES DOWN, RISK UP

Noble's troubles and Glencore's strength are not the only reasons for the malaise.

Unlike many other markets, no single exchange has attracted enough liquidity to hedge reliably.

Instead bourses like ICE, CME and others including China's Zhengzhou Commodity Exchange (ZCE), Singapore Exchange (>> Singapore Exchange Limited) or the European Energy Exchange offer contracts with varying delivery options, differing underlying coal qualities, and in various currencies.

Chinese exchanges like ZCE <0#CZC> have grown somewhat, but months can still pass without trades, and Chinese coal futures are problematic for international traders.

"There has been quite a bit of turmoil in the coal trading business," said Ben Tait, analyst at British energy consultancy Prospex Research. "China is the driver. Its coal policy shifts can make prices soar or plunge. This has led to some big trading losses."

Yet not everybody sees only doom and gloom.

RWE's Hall said he hoped liquidity would gradually improve again over time, something Pat Markey, managing director of Singapore's Sierra Vista Resources, also expected.

"The Asian market is poised for growth in financial trading, but this will take time as the Asian market is quite fragmented," Markey said.

(For a graphic on coal consumption by region, click http://bit.ly/2yKQt8Y)

(Editing by Lincoln Feast)

By Henning Gloystein and Vera Eckert