"More and more trust products will come due in the coming quarters," said Wang Tao, chief China economist with UBS. "With the very rapid growth and an average maturity of two years, more trusts are set to come due each quarter, and some may need to be rolled over or allocated fresh funding. As such, the risk of further trust repayment issues or default is set to rise."

"Basic industries, including mining and materials, are the major destinations for trust investment, while based on the gloomy industry outlook, the products have high possibilities of default," said Wayne Lu, a product manager with a mid-sized trust company in Shanghai.

Shaky trust product promises repayment

Trust firms' revenues at risk

Slowing economic growth and anti-pollution policies have dragged coal prices to nearly a four-year low. Among the 15 listed companies that released annual reports Monday, 13 reported big declines in profit during 2013.

Repayment difficulties have emerged among coal firms other than Shanxi Liansheng Energy. Another miner, Shanxi Zhenfu Energy, was unable to meet its liabilities in January, causing agent China Credit Trust problems in redemption of its 3 billion yuan in high-yield trust products.

China's trust sector has been one of the fastest-growing types of non-bank, or "shadow banking", credit. As of the third quarter last year, overall trust assets reached about 10 trillion yuan, up from 2 trillion at the end of 2009 and accounting for about 9 percent of overall credit in the system, according to UBS.

Analysts have argued that China should tolerate trust product defaults in order to teach investors a lesson about the risk of high-yield investments.

But some said defaults would lead to a loss of confidence in China's trust and other shadow credit markets, as well as a shrinkage of liquidity in those markets and a systemic credit crunch.

Local governments and financial institutions also have low tolerance for defaults out of a need to protect their reputations.

Since 2012, more than 20 trust products totaling 23.8 billion yuan have run into payment issues. About half of these cases are still in court, though in most cases, investors have been paid either by trust companies or their linked guarantors, Wang said.

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